path: root/utilities/gm.1

.TH gm 1 "2022/03/11" "GraphicsMagick"
.TP
.in 15
.in 15
.in 20
.SH NAME

gm - command-line utility to create, edit, compare, convert, or display images

.SH SYNOPSIS

\fBgm animate\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fIfile\fP \fB[ [\fP
\fIoptions ...\fP \fB]\fP \fIfile ...\fP \fB]\fP

\fBgm batch\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fB[\fP \fIscript\fP \fB]\fP

\fBgm benchmark\fP \fB[\fP \fIoptions ...\fP \fB]\fP subcommand

\fBgm compare\fP \fB[\fP \fIoptions\fP \fB... ]\fP \fIreference-image\fP
\fB[\fP \fIoptions\fP \fB... ]\fP \fIcompare-image\fP
\fB[\fP \fIoptions\fP \fB... ]\fP

\fBgm composite\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fIchange-image base-image\fP
\fB[\fP \fImask-image\fP \fB]\fP \fIoutput-image\fP

\fBgm conjure\fP \fB[\fP \fIoptions\fP \fB]\fP \fIscript.msl\fP
\fB[ [\fP \fIoptions\fP \fB]\fP \fIscript.msl\fP \fB]\fP

\fBgm convert\fP \fB[ [\fP \fIoptions ...\fP \fB] [\fP \fIinput-file ...\fP
\fB] [\fP \fIoptions ...\fP \fB] ]\fP \fIoutput-file\fP 

\fBgm display\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fIfile ...\fP
\fB[ [\fP\fIoptions ...\fP \fB]\fP\fIfile ...\fP \fB]\fP

\fBgm identify\fP \fIfile\fP \fB[\fP \fIfile ...\fP \fB]\fP

\fBgm import\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fIfile\fP

\fBgm mogrify\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fIfile ...\fP

\fBgm montage\fP \fB[\fP \fIoptions ...\fP \fB]\fP \fIfile\fP \fB[ [\fP
\fIoptions ...\fP \fB]\fP \fIfile ...\fP \fB]\fP \fIoutput-file\fP

\fBgm time\fP subcommand

\fBgm version\fP
.SH DESCRIPTION

GraphicsMagick's \fBgm\fP provides a suite of utilities for creating,
comparing, converting, editing, and displaying images.  All of the
utilities are provided as sub-commands of a single \fBgm\fP
executable.  The \fBgm\fP executable returns the exit code 0 to
indicate success, or 1 to indicate failure:

\fBanimate\fP
displays an animation (e.g. a GIF file) on any workstation display
running an \fIX\fP server.

\fBbatch\fP
executes an arbitary number of the utility commands
(e.g. \fBconvert\fP) in the form of a simple linear batch script in
order to improve execution efficiency, and/or to allow use as a
subordinate co-process under the control of an arbitrary script or
program.

\fBbenchmark\fP
executes one of the other utility commands (e.g. \fBconvert\fP) for a
specified number of iterations, or execution time, and reports
execution time and other profiling information such as CPU
utilization. \fBBenchmark\fP provides various operating modes
including executing the command with a varying number of threads, and
alternate reporting formats such as comma-separated value (CSV).

\fBcompare\fP
compares two images and reports difference statistics according to
specified metrics and/or outputs an image with a visual representation
of the differences.  It may also be used to test if images are similar
within a particular range and specified metric, returning a truth
value to the executing environment.

\fBcomposite\fP
composites images (blends or merges images together) to create new images.

\fBconjure\fP
interprets and executes scripts in
the Magick Scripting Language (MSL).

\fBconvert\fP
converts an input file using one image format to an output file with
the same or differing image format while applying an arbitrary number
of image transformations.

\fBdisplay\fP
is a machine architecture independent image processing and display
facility. It can display an image on any workstation display running
an \fIX\fP server.

\fBidentify\fP
describes the format and characteristics of one or more image
files. It will also report if an image is incomplete or corrupt.

\fBimport\fP
reads an image from any visible window on an \fIX\fP server and
outputs it as an image file. You can capture a single window, the
entire screen, or any rectangular portion of the screen.

\fBmogrify\fP
transforms an image or a sequence of images. These transforms include
\fBimage scaling\fP, \fBimage rotation\fP, \fBcolor reduction\fP,
and others. The transmogrified image \fBoverwrites\fP the original
image.

\fBmontage\fP
creates a composite by combining several separate images. The images
are tiled on the composite image with the name of the image optionally
appearing just below the individual tile.

\fBtime\fP
executes a subcommand and reports the user, system, and total
execution time consumed.

\fBversion\fP
reports the GraphicsMagick release version, maximum sample-depth,
copyright notice, supported features, and the options used while
building the software.

The \fBGraphicsMagick\fP utilities recognize the following image formats:


\fBName\fP  \fBMode\fP \fBDescription\fP
 o  3FR       r-- Hasselblad Photo RAW
 o  8BIM      rw- Photoshop resource format
 o  8BIMTEXT  rw- Photoshop resource text format
 o  8BIMWTEXT rw- Photoshop resource wide text format
 o  APP1      rw- Raw application information
 o  APP1JPEG  rw- Raw JPEG binary data
 o  ART       r-- PF1: 1st Publisher
 o  ARW       r-- Sony Alpha DSLR RAW
 o  AVS       rw+ AVS X image
 o  BIE       rw- Joint Bi-level Image experts Group
                  interchange format
 o  BMP       rw+ Microsoft Windows bitmap image
 o  BMP2      -w- Microsoft Windows bitmap image v2
 o  BMP3      -w- Microsoft Windows bitmap image v3
 o  CACHE     --- Magick Persistent Cache image format
 o  CALS      rw- Continuous Acquisition and Life-cycle
                  Support Type 1 image
 o  CAPTION   r-- Caption (requires separate size info)
 o  CIN       rw- Kodak Cineon Format
 o  CMYK      rw- Raw cyan, magenta, yellow, and black
                  samples (8 or 16 bits, depending on
                  the image depth)
 o  CMYKA     rw- Raw cyan, magenta, yellow, black, and
                  matte samples (8 or 16 bits, depending
                  on the image depth)
 o  CR2       r-- Canon Photo RAW
 o  CRW       r-- Canon Photo RAW
 o  CUR       r-- Microsoft Cursor Icon
 o  CUT       r-- DR Halo
 o  DCM       r-- Digital Imaging and Communications in
                  Medicine image
 o  DCR       r-- Kodak Photo RAW
 o  DCX       rw+ ZSoft IBM PC multi-page Paintbrush
 o  DNG       r-- Adobe Digital Negative
 o  DPS       r-- Display PostScript Interpreter
 o  DPX       rw- Digital Moving Picture Exchange
 o  EPDF      rw- Encapsulated Portable Document Format
 o  EPI       rw- Adobe Encapsulated PostScript
                  Interchange format
 o  EPS       rw- Adobe Encapsulated PostScript
 o  EPS2      -w- Adobe Level II Encapsulated PostScript
 o  EPS3      -w- Adobe Level III Encapsulated PostScript
 o  EPSF      rw- Adobe Encapsulated PostScript
 o  EPSI      rw- Adobe Encapsulated PostScript
                  Interchange format
 o  EPT       rw- Adobe Encapsulated PostScript with MS-DOS
                  TIFF preview
 o  EPT2      rw- Adobe Level II Encapsulated PostScript
                  with MS-DOS TIFF preview
 o  EPT3      rw- Adobe Level III Encapsulated PostScript
                  with MS-DOS TIFF preview
 o  EXIF      rw- Exif digital camera binary data
 o  FAX       rw+ Group 3 FAX (Not TIFF Group3 FAX!)
 o  FITS      rw- Flexible Image Transport System
 o  FRACTAL   r-- Plasma fractal image
 o  FPX       rw- FlashPix Format
 o  GIF       rw+ CompuServe graphics interchange format
 o  GIF87     rw- CompuServe graphics interchange format
                  (version 87a)
 o  GRADIENT  r-- Gradual passing from one shade to
                  another
 o  GRAY      rw+ Raw gray samples (8/16/32 bits,
                  depending on the image depth)
 o  HISTOGRAM -w- Histogram of the image
 o  HRZ       r-- HRZ: Slow scan TV
 o  HTML      -w- Hypertext Markup Language and a
                  client-side image map
 o  ICB       rw+ Truevision Targa image
 o  ICC       rw- ICC Color Profile
 o  ICM       rw- ICC Color Profile
 o  ICO       r-- Microsoft icon
 o  ICON      r-- Microsoft icon
 o  IDENTITY  r-- Hald CLUT identity image
 o  IMAGE     r-- GraphicsMagick Embedded Image
 o  INFO      -w+ Image descriptive information and
                   statistics
 o  IPTC      rw- IPTC Newsphoto
 o  IPTCTEXT  rw- IPTC Newsphoto text format
 o  IPTCWTEXT rw- IPTC Newsphoto wide text format
 o  JBG       rw+ Joint Bi-level Image experts Group
                  interchange format
 o  JBIG      rw+ Joint Bi-level Image experts Group
                  interchange format
 o  JNG       rw- JPEG Network Graphics
 o  JP2       rw- JPEG-2000 JP2 File Format Syntax
 o  JPC       rw- JPEG-2000 Code Stream Syntax
 o  JPEG      rw- Joint Photographic Experts Group
                  JFIF format
 o  JPG       rw- Joint Photographic Experts Group
                  JFIF format
 o  K25       r-- Kodak Photo RAW
 o  KDC       r-- Kodak Photo RAW
 o  LABEL     r-- Text image format
 o  M2V       rw+ MPEG-2 Video Stream
 o  MAP       rw- Colormap intensities and indices
 o  MAT       r-- MATLAB image format
 o  MATTE     -w+ MATTE format
 o  MIFF      rw+ Magick Image File Format
 o  MNG       rw+ Multiple-image Network Graphics
 o  MONO      rw- Bi-level bitmap in least-significant-
                  -byte-first order
 o  MPC       rw+ Magick Persistent Cache image format
 o  MPEG      rw+ MPEG-1 Video Stream
 o  MPG       rw+ MPEG-1 Video Stream
 o  MRW       r-- Minolta Photo Raw
 o  MSL       r-- Magick Scripting Language
 o  MTV       rw+ MTV Raytracing image format
 o  MVG       rw- Magick Vector Graphics
 o  NEF       r-- Nikon Electronic Format
 o  NULL      r-- Constant image of uniform color
 o  OTB       rw- On-the-air bitmap
 o  P7        rw+ Xv thumbnail format
 o  PAL       rw- 16bit/pixel interleaved YUV
 o  PALM      rw- Palm Pixmap
 o  PBM       rw+ Portable bitmap format (black and white)
 o  PCD       rw- Photo CD
 o  PCDS      rw- Photo CD
 o  PCL       -w- Page Control Language
 o  PCT       rw- Apple Macintosh QuickDraw/PICT
 o  PCX       rw- ZSoft IBM PC Paintbrush
 o  PDB       rw+ Palm Database ImageViewer Format
 o  PDF       rw+ Portable Document Format
 o  PEF       r-- Pentax Electronic File
 o  PFA       r-- TrueType font
 o  PFB       r-- TrueType font
 o  PGM       rw+ Portable graymap format (gray scale)
 o  PGX       r-- JPEG-2000 VM Format
 o  PICON     rw- Personal Icon
 o  PICT      rw- Apple Macintosh QuickDraw/PICT
 o  PIX       r-- Alias/Wavefront RLE image format
 o  PLASMA    r-- Plasma fractal image
 o  PNG       rw- Portable Network Graphics
 o  PNG24     rw- Portable Network Graphics, 24 bit RGB
                  opaque only
 o  PNG32     rw- Portable Network Graphics, 32 bit RGBA
                  semitransparency OK
 o  PNG8      rw- Portable Network Graphics, 8-bit
                  indexed, binary transparency only
 o  PNM       rw+ Portable anymap
 o  PPM       rw+ Portable pixmap format (color)
 o  PREVIEW   -w- Show a preview an image enhancement,
                  effect, or f/x
 o  PS        rw+ Adobe PostScript
 o  PS2       -w+ Adobe Level II PostScript
 o  PS3       -w+ Adobe Level III PostScript
 o  PSD       rw- Adobe Photoshop bitmap
 o  PTIF      rw- Pyramid encoded TIFF
 o  PWP       r-- Seattle Film Works
 o  RAF       r-- Fuji Photo RAW
 o  RAS       rw+ SUN Rasterfile
 o  RGB       rw+ Raw red, green, and blue samples
 o  RGBA      rw+ Raw red, green, blue, and matte samples
 o  RLA       r-- Alias/Wavefront image
 o  RLE       r-- Utah Run length encoded image
 o  SCT       r-- Scitex HandShake
 o  SFW       r-- Seattle Film Works
 o  SGI       rw+ Irix RGB image
 o  SHTML     -w- Hypertext Markup Language and a
                  client-side image map
 o  STEGANO   r-- Steganographic image
 o  SUN       rw+ SUN Rasterfile
 o  SVG       rw+ Scalable Vector Gaphics
 o  TEXT      rw+ Raw text
 o  TGA       rw+ Truevision Targa image
 o  TIFF      rw+ Tagged Image File Format
 o  TILE      r-- Tile image with a texture
 o  TIM       r-- PSX TIM
 o  TOPOL     r-- TOPOL X Image
 o  TTF       r-- TrueType font
 o  TXT       rw+ Raw text
 o  UIL       -w- X-Motif UIL table
 o  UYVY      rw- 16bit/pixel interleaved YUV
 o  VDA       rw+ Truevision Targa image
 o  VICAR     rw- VICAR rasterfile format
 o  VID       rw+ Visual Image Directory
 o  VIFF      rw+ Khoros Visualization image
 o  VST       rw+ Truevision Targa image
 o  WBMP      rw- Wireless Bitmap (level 0) image
 o  WMF       r-- Windows Metafile
 o  WPG       r-- Word Perfect Graphics
 o  X         rw- X Image
 o  X3F       r-- Foveon X3 (Sigma/Polaroid) RAW
 o  XBM       rw- X Windows system bitmap (black
                  and white)
 o  XC        r-- Constant image uniform color
 o  XCF       r-- GIMP image
 o  XMP       rw- Adobe XML metadata
 o  XPM       rw- X Windows system pixmap (color)
 o  XV        rw+ Khoros Visualization image
 o  XWD       rw- X Windows system window dump (color)
 o  YUV       rw- CCIR 601 4:1:1 or 4:2:2 (8-bit only)
                  
    Modes:        
              r   Read
              w   Write
              +   Multi-image


\fISupport for some of these formats require additional programs or libraries.
See README
in the source package for where to find optional additional software\fP.

Note, a format delineated with + means that if more than one
image is specified, frames are combined into a single multi-image
file. Use \fB+adjoin\fP if you want a single image produced for each
frame.

Your installation might not support all of the formats in the list.
To get an accurate listing of the formats supported by your particular
configuration, run "gm convert -list format".

Raw images are expected to have one byte per pixel unless \fBgm\fP is
compiled in 16-bit quantum mode or in 32-bit quantum mode. Here, the
raw data is expected to be stored two or four bytes per pixel,
respectively, in most-significant-byte-first order.  For example, you
can tell if \fBgm\fP was compiled in 16-bit mode by typing "gm
version" without any options, and looking for "Q:16" in the first line
of output.
.SH FILES AND FORMATS

By default, the image format is determined by its magic number, i.e., the
first few bytes of the file. To specify
a particular image format, precede the filename with an image format name
and a colon (\fIi.e.\fP\fBps:image\fP) or specify the image type as the
filename suffix (\fIi.e.\fP\fBimage.ps\fP).
The magic number takes precedence over the filename suffix
and the prefix takes precedence over the magic number and the suffix
in input files.
When a file is read, its magic number is stored in the "image->magick"
string.
In output files, the prefix takes precedence over the filename suffix,
and the filename suffix takes precedence over the
"image->magick" string.

To read the "built-in" formats (GRANITE, H, LOGO,
NETSCAPE, PLASMA, and ROSE) use a prefix (including the colon) without a
filename or suffix.  To read the XC format, follow the colon with a color
specification.  To read the CAPTION format, follow the colon with a text
string or with a filename prefixed with the at symbol (\fB@\fP).


When you specify \fBX\fP as your image type, the filename has special
meaning. It specifies an X window by \fBid, name\fP, or
\fBroot\fP. If
no filename is specified, the window is selected by clicking the mouse
in the desired window.

Specify \fIinput_file\fP as \fB-\fP for standard input,
\fIoutput_file\fP as \fB-\fP for standard output.
If \fIinput_file\fP has the extension \fB.Z\fP or \fB.gz\fP, the
file is uncompressed with \fBuncompress\fP or \fBgunzip\fP
respectively.
If \fIoutput_file\fP has the extension \fB.Z\fP or \fB.gz\fP,
the file is compressed using with \fIcompress\fP or \fIgzip\fP respectively.

Use an optional index enclosed in brackets after an input file name to
specify a desired subimage of a multi-resolution image format like
Photo CD (e.g. "img0001.pcd[4]") or a range for MPEG images
(e.g. "video.mpg[50-75]"). A subimage specification can be
disjoint (e.g. "image.tiff[2,7,4]"). For raw images, specify
a subimage with a geometry (e.g. -size 640x512
"image.rgb[320x256+50+50]").  Surround the image name with
quotation marks to prevent your shell from interpreting the square
brackets. Single images are written with the filename you
specify. However, multi-part images (e.g., a multi-page PostScript
document with \fB+adjoin\fP specified) may be written with the scene
number included as part of the filename. In order to include the scene
number in the filename, it is necessary to include a printf-style
%d format specification in the file name and use the +adjoin
option. For example,

.nf
    image%02d.miff
.fi

writes files \fIimage00.miff, image01.miff,\fP etc. Only a single
specification is allowed within an output filename. If more than one
specification is present, it will be ignored. It is best to embed the
scene number in the base part of the file name, not in the extension,
because the extension will not be a recognizeable image type.

When running a commandline utility, you can
prepend an at sign @ to a filename to read a list of image
filenames from that file. This is convenient in the event you have too
many image filenames to fit on the command line.
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images that follows,
until the set is terminated by the appearance of any option or \fB-noop\fP.
Some options only affect the decoding of images and others only the encoding.
The latter can appear after the final group of input images.

This is a combined list of the command-line options used by the
GraphicsMagick utilities (\fIanimate\fP, \fIcompare\fP,
\fIcomposite\fP, \fIconvert\fP, \fIdisplay\fP, \fIidentify\fP,
\fIimport\fP, \fImogrify\fP and \fImontage\fP).


In this document, angle brackets ("<>") enclose variables and curly
brackets ("{}") enclose optional parameters. For example,
"\fB-fuzz <distance>{%}\fP" means you can use the
option "-fuzz 10"
or "-fuzz 2%".

.TP
.B "-adjoin"
\fRjoin images into a single multi-image file

By default, all images of an image sequence are stored in the same
file. However, some formats (e.g. JPEG) do not support storing more
than one image per file and only the first frame in an image sequence
will be saved unless the result is saved to separate files. Use
\fB+adjoin\fP to force saving multiple frames to multiple numbered
files. If \fB+adjoin\fP is used, then the output filename must
include a printf style formatting specification for the numeric part
of the filename.  For example,

.nf
    image%02d.miff
.fi
.TP
.B "-affine \fI<matrix>"\fP
\fRdrawing transform matrix

This option provides a transform matrix {sx,rx,ry,sy,tx,ty} for
use by subsequent \fB-draw\fP or \fB-transform\fP options.
.TP
.B "-antialias"
\fRremove pixel aliasing

By default antialiasing algorithms are used when drawing objects (e.g. lines)
or rendering vector formats (e.g. WMF and Postscript). Use +antialias to
disable use of antialiasing algorithms. Reasons to disable antialiasing
include avoiding increasing colors in the image, or improving rendering speed.
.TP
.B "-append"
\fRappend a set of images

This option creates a single image where the images in the original set
are stacked top-to-bottom.  If they are not of the same width,
any narrow images will be expanded to fit using the background color.
Use \fB+append\fP to stack images left-to-right.  The set of images
is terminated by the appearance of any option.
If the \fB-append\fP
option appears after all of the input images, all images are appended.
.TP
.B "-asc-cdl \fI<spec>"\fP
\fRapply ASC CDL color transform

Applies ("bakes in") the ASC CDL, which is a format for the exchange
of basic primary color grading information between equipment and
software from different manufacturers. The format defines the math for
three functions: slope, offset and power. Each function uses a number
for the red, green, and blue color channels for a total of nine
numbers comprising a single color decision. The tenth number
(optional) is for chromiance (saturation) as specified by ASC CDL
1.2.

The argument string is comma delimited and is in the following form
(but without invervening spaces or line breaks)

.nf
    redslope,redoffset,redpower:
    greenslope,greenoffset,greenpower:
    blueslope,blueoffset,bluepower:
    saturation
.fi

with the unity (no change) specification being:

.nf
    "1.0,0.0,1.0:1.0,0.0,1.0:1.0,0.0,1.0:1.0"
.fi
.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password

Use this option to supply a password for decrypting an image or an
image sequence, if it is being read from a format such as PDF that supports
encryption.  Encrypting images being written is not supported.
.TP
.B "-auto-orient"
\fRorient (rotate) image so it is upright

Adjusts the image orienation so that it is suitable for viewing.  Uses
the orientation tag obtained from the image file or as supplied by the
\fB-orient\fP option.
.TP
.B "-average"
\fRaverage a set of images

The set of images
is terminated by the appearance of any option.
If the \fB-average\fP
option appears after all of the input images, all images are averaged.
.TP
.B "-backdrop"
\fRdisplay the image centered on a backdrop.

This backdrop covers the entire workstation screen and is useful for hiding
other X window activity while viewing the image. The color of the backdrop
is specified as the foreground color (X11 default is black).
Refer to
"X Resources", below,
for details.
.TP
.B "-background \fI<color>"\fP
\fRthe background color

The color is specified using the format described under the \fB-fill\fP
option.
.TP
.B "-black-threshold \fIred[,green][,blue][,opacity]"\fP
\fRpixels below the threshold become black

Use \fB-black-threshold\fP to set pixels with values below the specified
threshold to minimum value (black). If only one value is supplied, or the
red, green, and blue values are identical, then intensity thresholding is
used. If the color threshold values are not identical then channel-based
thresholding is used, and color distortion will occur. Specify a negative
value (e.g. -1) if you want a channel to be ignored but you do want to
threshold a channel later in the list. If a percent (%) symbol is
appended, then the values are treated as a percentage of maximum
range.
.TP
.B "-blue-primary \fI<x>,<y>"\fP
\fRblue chromaticity primary point
.TP
.B "-blur \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator

Blur with the given radius and
standard deviation (sigma).
.TP
.B "-border \fI<width>x<height>"\fP
\fRsurround the image with a border of color

See \fB-geometry\fP for details
about the geometry specification.
.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color

The color is specified using the format described under the \fB-fill\fP
option.
.TP
.B "-borderwidth \fI<geometry>"\fP
\fRthe border width
.TP
.B "-box \fI<color>"\fP
\fRset the color of the annotation bounding box

The color is specified using the format described under the \fB-fill\fP
option.

See \fB-draw\fP for further
details.
.TP
.B "-channel \fI<type>"\fP
\fRthe type of channel

Choose from: \fBRed\fP, \fBGreen\fP, \fBBlue\fP, \fBOpacity\fP,
\fBMatte\fP, \fBCyan\fP, \fBMagenta\fP, \fBYellow\fP, \fBBlack\fP,
or \fBGray\fP.

Use this option to extract a particular \fIchannel\fP from the image.
\fBOpacity\fP,
for example, is useful for extracting the opacity values from an image.
.TP
.B "-charcoal \fI<factor>"\fP
\fRsimulate a charcoal drawing
.TP
.B "-chop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRremove pixels from the interior of an image

\fIWidth\fP and \fIheight\fP give the number of columns and rows to remove,
and \fIx\fP and \fIy\fP are offsets that give the location of the
leftmost column and topmost row to remove.

The \fIx\fP offset normally specifies the leftmost column to remove.
If the \fB-gravity\fP option is present with \fINorthEast, East,\fP
or \fISouthEast\fP
gravity, it gives the distance leftward from the right edge
of the image to the rightmost column to remove.  Similarly, the \fIy\fP offset
normally specifies the topmost row to remove, but if
the \fB-gravity\fP option is present with \fISouthWest, South,\fP
or \fISouthEast\fP
gravity, it specifies the distance upward from the bottom edge of the
image to the bottom row to remove.

The \fB-chop\fP option removes entire rows and columns,
and moves the remaining corner blocks leftward and upward to close the gaps.
.TP
.B "-clip"
\fRapply the clipping path, if one is present

If a clipping path is present, it will be applied to subsequent operations.

For example, if you type the following command:

.nf
    gm convert -clip -negate cockatoo.tif negated.tif
.fi

only the pixels within the clipping path are negated.

The \fB-clip\fP feature requires the XML library.  If the XML library
is not present, the option is ignored.
.TP
.B "-coalesce"
\fRmerge a sequence of images

Each image N in the sequence after Image 0 is replaced with the image
created by flattening images 0 through N.

The set of images
is terminated by the appearance of any option.
If the \fB-coalesce\fP
option appears after all of the input images, all images are coalesced.
.TP
.B "-colorize \fI<value>"\fP
\fRcolorize the image with the pen color

Specify the amount of colorization as a percentage. You can apply separate
colorization values to the red, green, and blue channels of the image with
a colorization value list delimited with slashes (e.g. 0/0/50).

The \fB-colorize\fP option may be used in conjunction with \fB-modulate\fP
to produce a nice sepia toned image like:

.nf
    gm convert input.ppm -modulate 115,0,100 \\
              -colorize 7,21,50 output.ppm.
.fi
.TP
.B "-colormap \fI<type>"\fP
\fRdefine the colormap type

Choose between \fBshared\fP or \fBprivate\fP.

This option only applies when the default X server visual is \fIPseudoColor\fP
or \fIGRAYScale\fP. Refer to \fB-visual\fP for more details. By default,
a shared colormap is allocated. The image shares colors with other X clients.
Some image colors could be approximated, therefore your image may look
very different than intended. Choose \fBPrivate\fP and the image colors
appear exactly as they are defined. However, other clients may
go \fItechnicolor\fP when the image colormap is installed.
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image

The actual number of colors in the image may be less than your request,
but never more. Note, this is a color reduction option. Images with less
unique colors than specified with this option will have any duplicate or
unused colors removed. The ordering of an existing color palette may be
altered. When converting an image from color to grayscale, convert the
image to the gray colorspace before reducing the number of colors since
doing so is most efficient. Refer to <a
href="quantize.html">quantize for more details.

Note, options \fB-dither\fP, \fB-colorspace\fP, and \fB-treedepth\fP
affect the color reduction algorithm.
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace

Choices are:
\fBCineonLog\fP, \fBCMYK\fP, \fBGRAY\fP, \fBHSL\fP, \fBHWB\fP,
\fBOHTA\fP, \fBRGB\fP, \fBRec601Luma\fP, \fBRec709Luma\fP,
\fBRec601YCbCr\fP, \fBRec709YCbCr\fP, \fBTransparent\fP, \fBXYZ\fP,
\fBYCbCr\fP, \fBYIQ\fP, \fBYPbPr\fP, or \fBYUV\fP.

Color reduction, by default, takes place in the RGB color space. Empirical
evidence suggests that distances in color spaces such as YUV or YIQ correspond
to perceptual color differences more closely than do distances in RGB space.
These color spaces may give better results when color reducing an image.
Refer to quantize for more details.
Two gray colorspaces are supported. The \fBRec601Luma\fP space is
based on the recommendations for legacy NTSC television (ITU-R
BT.601-5).  The \fBRec709Luma\fP space is based on the
recommendations for HDTV (Rec. ITU-R BT.709-5) and is suitable for use
with computer graphics, and for contemporary CRT displays. The
\fBGRAY\fP colorspace currently selects the \fBRec601Luma\fP
colorspace by default for backwards compatibly reasons. This default
may be re-considered in the future.

Two YCbCr colorspaces are supported. The \fBRec601YCbCr\fP space is
based on the recommendations for legacy NTSC television (ITU-R BT.601-5). The
\fBRec709CbCr\fP space is based on the recommendations for HDTV (Rec.
ITU-R BT.709-5) and is suitable for suitable for use with computer
graphics, and for contemporary CRT displays. The \fBYCbCr\fP colorspace
specification is equivalent to\fBRec601YCbCr\fP.


The \fBTransparent\fP color space behaves uniquely in that it preserves
the matte channel of the image if it exists.

The \fB-colors\fP or \fB-monochrome\fP option, or saving to a file
format which requires color reduction, is required for this option to
take effect.
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment

Use this option to assign a specific comment to the image, when writing
to an image format that supports comments. You can include the
image filename, type, width, height, or other image attribute by embedding
special format characters listed under the \fB-format\fP option.
The comment is not drawn on the image, but is embedded in the image
datastream via a "Comment" tag or similar mechanism.  If you want the
comment to be visible on the image itself, use the \fB-draw\fP option
instead.

For example,

.nf
     -comment "%m:%f %wx%h"
.fi

produces an image comment of \fBMIFF:bird.miff 512x480\fP for an image
titled \fBbird.miff\fP and whose width is 512 and height is 480.

If the first character of \fIstring\fP is \fI@\fP, the image comment
is read from a file titled by the remaining characters in the string.
Please note that if the string comes from an untrusted source that it
should be sanitized before use since otherwise the content of an
arbitrary readable file could be incorporated in a comment in the
output file (a security risk).

If the -comment option appears multiple times, only the last comment is
stored.

In PNG images, the comment is stored in a \fBtEXt\fP or \fBzTXt\fP chunk
with the keyword "comment".
.TP
.B "-compose \fI<operator>"\fP
\fRthe type of image composition

The description of composition uses abstract terminology in order to
allow the the description to be more clear, while avoiding constant
values which are specific to a particular build configuration. Each image
pixel is represented by red, green, and blue levels (which are equal for
a gray pixel). MaxRGB is the maximum integral value which may be stored
in the red, green, or blue channels of the image. Each image pixel may
also optionally (if the image matte channel is enabled) have an
associated level of opacity (ranging from opaque to transparent), which
may be used to determine the influence of the pixel color when
compositing the pixel with another image pixel. If the image matte
channel is disabled, then all pixels in the image are treated as opaque.
The color of an \fIopaque\fP pixel is fully visible while the color of a
\fItransparent\fP pixel color is entirely absent (pixel color is ignored).

By definition, raster images have a rectangular shape. All image rows are
of equal length, and all image columns have the same number of rows. By
treating the opacity channel as a visual "mask" the rectangular image may
be given a "shape" by treating the opacity channel as a cookie-cutter for
the image. Pixels within the shape are opaque, while pixels outside the
shape are transparent. Pixels on the boundary of the shape may be between
opaque and transparent in order to provide antialiasing (visually smooth
edges). The description of the composition operators use this concept of
image "shape" in order to make the description of the operators easier to
understand. While it is convenient to describe the operators in terms of
"shapes" they are by no means limited to mask-style operations since they
are based on continuous floating-point mathematics rather than simple
boolean operations.

By default, the \fIOver\fP composite operator is used. The following
composite operators are available:

.nf
     Over
     In
     Out
     Atop
     Xor
     Plus
     Minus
     Add
     Subtract
     Difference
     Divide
     Multiply
     Bumpmap
     Copy
     CopyRed
     CopyGreen
     CopyBlue
     CopyOpacity
     CopyCyan
     CopyMagenta
     CopyYellow
     CopyBlack
.fi

The behavior of each operator is described below.

.in 15

.in 15
.B "Over"
.in 20
 \fR
.in 20
The result will be the union of the two image shapes, with opaque areas
of \fIchange-image\fP obscuring \fIbase-image\fP in the region of
overlap.

.in 15
.in 15
.B "In"
.in 20
 \fR
.in 20
The result is simply \fIchange-image\fP cut by the shape of
\fIbase-image\fP. None of the image data of \fIbase-image\fP will be in
the result.

.in 15
.in 15
.B "Out"
.in 20
 \fR
.in 20
The resulting image is \fIchange-image\fP with the shape of
\fIbase-image\fP cut out.

.in 15
.in 15
.B "Atop"
.in 20
 \fR
.in 20
The result is the same shape as \fIbase-image\fP, with
\fIchange-image\fP obscuring \fIbase-image\fP where the image shapes
overlap. Note this differs from \fBover\fP because the portion of
\fIchange-image\fP outside \fIbase-image\fP's shape does not appear in
the result.

.in 15
.in 15
.B "Xor"
.in 20
 \fR
.in 20
The result is the image data from both \fIchange-image\fP and
\fIbase-image\fP that is outside the overlap region. The overlap region
will be blank.

.in 15
.in 15
.B "Plus"
.in 20
 \fR
.in 20
The result is just the sum of the image data. Output values are cropped
to MaxRGB (no overflow). This operation is independent of the matte
channels.

.in 15
.in 15
.B "Minus"
.in 20
 \fR
.in 20
The result of \fIchange-image\fP - \fIbase-image\fP, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).

.in 15
.in 15
.B "Add"
.in 20
 \fR
.in 20
The result of \fIchange-image\fP + \fIbase-image\fP, with overflow
wrapping around (\fImod\fP MaxRGB+1).

.in 15
.in 15
.B "Subtract"
.in 20
 \fR
.in 20
The result of \fIchange-image\fP - \fIbase-image\fP, with underflow
wrapping around (\fImod\fP MaxRGB+1). The \fBadd\fP and \fBsubtract\fP
operators can be used to perform reversible transformations.

.in 15
.in 15
.B "Difference"
.in 20
 \fR
.in 20
The result of abs(\fIchange-image\fP - \fIbase-image\fP). This is
useful for comparing two very similar images.

.in 15
.in 15
.B "Divide"
.in 20
 \fR
.in 20
The result of \fIchange-image\fP / \fIbase-image\fP. This is useful
for improving the readability of text on unevenly illuminated photos (by
using a gaussian blurred copy of change-image as base-image).

.in 15
.in 15
.B "Multiply"
.in 20
 \fR
.in 20
The result of \fIchange-image\fP * \fIbase-image\fP. This is useful for
the creation of drop-shadows.

.in 15
.in 15
.B "Bumpmap"
.in 20
 \fR
.in 20
The result \fIbase-image\fP shaded by \fIchange-image\fP.

.in 15
.in 15
.B "Copy"
.in 20
 \fR
.in 20
The resulting image is \fIbase-image\fP replaced with
\fIchange-image\fP. Here the matte information is ignored.

.in 15
.in 15
.B "CopyRed"
.in 20
 \fR
.in 20
The resulting image is the red channel in \fIbase-image\fP replaced with
the red channel in \fIchange-image\fP. The other channels are copied
untouched.

.in 15
.in 15
.B "CopyGreen"
.in 20
 \fR
.in 20
The resulting image is the green channel in \fIbase-image\fP replaced
with the green channel in \fIchange-image\fP. The other channels are
copied untouched.

.in 15
.in 15
.B "CopyBlue"
.in 20
 \fR
.in 20
The resulting image is the blue channel in \fIbase-image\fP replaced
with the blue channel in \fIchange-image\fP. The other channels are
copied untouched.

.in 15
.in 15
.B "CopyOpacity"
.in 20
 \fR
.in 20
The resulting image is the opacity channel in \fIbase-image\fP replaced
with the opacity channel in \fIchange-image\fP. The other channels are
copied untouched.

.in 15
.in 15
.B "CopyCyan"
.in 20
 \fR
.in 20
The resulting image is the cyan channel in \fIbase-image\fP replaced
with the cyan channel in \fIchange-image\fP. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.

.in 15
.in 15
.B "CopyMagenta"
.in 20
 \fR
.in 20
The resulting image is the magenta channel in \fIbase-image\fP
replaced with the magenta channel in \fIchange-image\fP. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.

.in 15
.in 15
.B "CopyYellow"
.in 20
 \fR
.in 20
The resulting image is the yellow channel in \fIbase-image\fP
replaced with the yellow channel in \fIchange-image\fP. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.

.in 15
.in 15
.B "CopyBlack"
.in 20
 \fR
.in 20
The resulting image is the black channel in \fIbase-image\fP
replaced with the black channel in \fIchange-image\fP. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace. If change-image is not in CMYK
space, then the change-image pixel intensities are used.

.in 15


.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression

Choices are: \fINone\fP, \fIBZip\fP, \fIFax\fP,
\fIGroup3\fP, \fIGroup4\fP,
\fIJPEG\fP, \fILossless\fP,
\fILZW\fP, \fIRLE\fP, \fIZip\fP, \fILZMA\fP, \fIJPEG2000\fP,
\fIJPEG2000\fP, \fIJBIG\fP, \fIJBIG2\fP, \fIWebP\fP, or \fIZSTD\fP.


Specify \fB+compress\fP to store the binary image in an uncompressed format.
The default is the compression type of the specified image file.

\fI"Lossless"\fP refers to lossless JPEG, which is only available if
the JPEG library has been patched to support it. Use of lossless JPEG is
generally not recommended.

Use the \fB-quality\fP option to set the compression level to be used
by the JPEG, JPEG-2000, PNG, MIFF, MPEG, and TIFF encoders. Use the
\fB-sampling-factor\fP option to set the sampling factor to be used
by the DPX, JPEG, MPEG, and YUV encoders for downsampling the chroma
channels.
.TP
.B "-contrast"
\fRenhance or reduce the image contrast

This option enhances the intensity differences between the lighter and
darker elements of the image. Use \fB-contrast\fP to enhance
the image
or \fB+contrast\fP to reduce the image contrast.


For a more pronounced effect you can repeat the option:

.nf
    gm convert rose: -contrast -contrast rose_c2.png
.fi
.TP
.B "-convolve \fI<kernel>"\fP
\fRconvolve image with the specified convolution kernel

The kernel is specified as a comma-separated list of floating point
values, ordered left-to right, starting with the top row. The order of
the kernel is determined by the square root of the number of entries.
Presently only square kernels are supported.
.TP
.B "-create-directories"
\fRcreate output directory if required

Use this option with \fB-output-directory\fP if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory.  Without this option, \fBmogrify\fP will fail if the
required output directory does not exist.
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image

See \fB-geometry\fP for details
about the geometry specification.

The width and height give the size of the image that remains after cropping,
and \fIx\fP and \fIy\fP are offsets that give the location of the top left
corner of the cropped
image with respect to the original image.  To specify the amount to be
removed, use \fB-shave\fP instead.

If the \fIx\fP and \fIy\fP offsets are present, a single image is
generated, consisting of the pixels from the cropping region.
The offsets specify the location of the upper left corner of
the cropping region measured downward and rightward with respect to the
upper left corner of the image.
If the \fB-gravity\fP option is present with \fINorthEast, East,\fP
or \fISouthEast\fP
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region.  Similarly, if
the \fB-gravity\fP option is present with \fISouthWest, South,\fP
or \fISouthEast\fP
gravity, the distance is measured upward between the bottom
edges.

If the \fIx\fP and \fIy\fP offsets are omitted, a set of tiles of the
specified geometry, covering the entire input image, is generated.  The
rightmost tiles and the bottom tiles are smaller if the
specified geometry extends beyond the dimensions of the input image.
.TP
.B "-cycle \fI<amount>"\fP
\fRdisplace image colormap by amount

\fIAmount\fP defines the number of positions each colormap entry isshifted.

.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout

The events parameter specifies which events are to be logged.  It
can be either None, All, or a comma-separated list
consisting of one or more of the following domains:
Annotate,
Blob,
Cache,
Coder,
Configure,
Deprecate,
Error,
Exception,
FatalError,
Information,
Locale,
Option,
Render,
Resource,
TemporaryFile,
Transform,
User.
Warning, or
X11,
For example, to log cache and blob events, use

.nf
    gm convert -debug "Cache,Blob" rose: rose.png
.fi

The "User" domain is normally empty, but developers can log "User" events
in their private copy of GraphicsMagick.

Use the \fB-log\fP option to specify the format for debugging output.

Use \fB+debug\fP to turn off all logging.

An alternative to using \fB-debug\fP is to use the \fBMAGICK_DEBUG\fP
environment variable. The allowed values for the \fBMAGICK_DEBUG\fP
environment variable are the same as for the \fB-debug\fP option.
.TP
.B "-deconstruct"
\fRbreak down an image sequence into constituent parts

This option compares each image with the next in a sequence and
returns the maximum bounding region of any pixel differences it discovers.
This method can undo a coalesced sequence returned by the
\fB-coalesce\fP option, and is useful for removing redundant information
from a GIF or MNG animation.

The sequence of images
is terminated by the appearance of any option.
If the \fB-deconstruct\fP
option appears after all of the input images, all images are deconstructed.
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
This option creates one or more definitions for coders and
decoders to use while reading and writing image data. Definitions
may be passed to coders and decoders to control options that are
specific to certain image formats. If \fIvalue\fP is missing for a
definition, an empty-valued definition of a flag will be created with
that name. This is used to control on/off options. Use +define
<key>,... to remove definitions previously created. Use
+define "*" to remove all existing definitions.

The following definitions may be created:

.in 15

.in 15
.B "cineon:colorspace={rgb|cineonlog}"
.in 20
 \fR
.in 20
Use the cineon:colorspace option when reading a Cineon file to
specify the colorspace the Cineon file uses. This overrides the colorspace
type implied by the DPX header (if any).

.in 15
.in 15
.B "dpx:bits-per-sample=<value>"
.in 20
 \fR
.in 20
If the dpx:bits-per-sample key is defined, GraphicsMagick will write
DPX images with the specified bits per sample, overriding any existing
depth value. If this option is not specified, then the value is based on
the existing image depth value from the original image file. The DPX
standard supports bits per sample values of 1, 8, 10, 12, and 16. Many
DPX readers demand a sample size of 10 bits with type A padding (see
below).

.in 15
.in 15
.B "dpx:colorspace={rgb|cineonlog}"
.in 20
 \fR
.in 20
Use the dpx:colorspace option when reading a DPX file to
specify the colorspace the DPX file uses. This overrides the colorspace
type implied by the DPX header (if any).

.in 15
.in 15
.B "dpx:packing-method={packed|a|b|lsbpad|msbpad}"
.in 20
 \fR
.in 20
DPX samples are output within 32-bit words. They may be tightly
packed end-to-end within the words ("packed"), padded with null bits to
the right of the sample ("a" or "lsbpad"), or padded with null bits to the
left of the sample ("b" or "msbpad"). This option only has an effect for
sample sizes of 10 or 12 bits. If samples are not packed, the DPX
standard recommends type A padding. Many DPX readers demand a sample size
of 10 bits with type A padding.

.in 15
.in 15
.B "dpx:pixel-endian={lsb|msb}"
.in 20
 \fR
.in 20
Allows the user to specify the endian order of the pixels when
reading or writing the DPX files. Sometimes this is useful if the file is
(or must be) written incorrectly so that the file header and the pixels
use different endianness.

.in 15
.in 15
.B "dpx:swap-samples={true|false}"
.in 20
 \fR
.in 15
.B "dpx:swap-samples-read={true|false}"
.in 20
 \fR
.in 15
.B "dpx:swap-samples-write={true|false}"
.in 20
 \fR
.in 20
GraphicsMagick strives to adhere to the DPX standard but certain
aspects of the standard can be quite confusing. As a result, some
10-bit DPX files have Red and Blue interchanged, or Cb and Cr
interchanged due to an different interpretation of the standard, or
getting the wires crossed. The swap-samples option may be supplied
when reading or writing in order to read or write using the necessary
sample order.  Use swap-samples-read when swapping should only occur
in the reader, or swap-samples-write when swapping should only occur
in the writer.

.in 15
.in 15
.B "gradient:direction={South|North|West|East|NorthWest|NorthEast|SouthWest|SouthEast}"
.in 20
 \fR
.in 20
By default, the gradient coder produces a gradient from top to
bottom ("South").  Since GraphicsMagick 1.3.35, the gradient direction
may be specified to produce gradient vectors according to a
gravity-like specification.  The arguments are \fBSouth\fP (Top to
Bottom), \fBNorth\fP (Bottom to Top), \fBWest\fP (Right to Left),
\fBEast\fP (Left to Right), \fBNorthWest\fP (Bottom-Right to
Top-Left), \fBNorthEast\fP (Bottom-Left to Top-Right),
\fBSouthWest\fP (Top-Right Bottom-Left), and \fBSouthEast\fP
(Top-Left to Bottom-Right).

.in 15
.in 15
.B "jp2:rate=<value>"
.in 20
 \fR
.in 20
Specify the compression factor to use while writing JPEG-2000
files. The compression factor is the reciprocal of the compression
ratio. The valid range is 0.0 to 1.0, with 1.0 indicating lossless
compression. If defined, this value overrides the -quality
setting. The default quality setting of 75 results in a rate value of
0.06641.

.in 15
.in 15
.B "jpeg:block-smoothing={true|false}"
.in 20
 \fR
.in 20
Enables or disables block smoothing when reading a JPEG file
(default enabled).

.in 15
.in 15
.B "jpeg:dct-method=<value>"
.in 20
 \fR
.in 20
Selects the IJG JPEG library DCT implementation to use. The
encoding implementations vary in speed and encoding error. The
available choices for \fBvalue\fP are \fBislow\fP, \fBifast\fP,
\fBfloat\fP, \fBdefault\fP and \fBfastest\fP. Note that
\fBfastest\fP might not necessarily be fastest on your CPU, depending
on the choices made when the JPEG library was built and how your CPU
behaves.

.in 15
.in 15
.B "jpeg:fancy-upsampling={true|false}"
.in 20
 \fR
.in 20
Enables or disables fancy upsampling when reading a JPEG file
(default enabled).

.in 15
.in 15
.B "jpeg:max-scan-number=<value>"
.in 20
 \fR
.in 20
Specifies an integer value for the maximum number of progressive
scans allowed in a JPEG file.  The default maximum is 100 scans.  This
limit is imposed due to a weakness in the JPEG standard which allows
small JPEG files to take many minutes or hours to be read.

.in 15
.in 15
.B "jpeg:max-warnings=<value>"
.in 20
 \fR
.in 20
Specifies an integer value for how many warnings are allowed for
any given error type before being promoted to a hard error.  JPEG
files producing excessive warnings indicate a problem with the file.

.in 15
.in 15
.B "jpeg:optimize-coding={true|false}"
.in 20
 \fR
.in 20
Selects if huffman encoding should be used. Huffman encoding is enabled
by default, but may be disabled for very large images since it encoding
requires that the entire image be buffered in memory. Huffman encoding
produces smaller JPEG files at the expense of added compression time and
memory consumption.

.in 15
.in 15
.B "jpeg:preserve-settings"
.in 20
 \fR
.in 20
If the jpeg:preserve-settings flag is defined, the JPEG encoder will
use the same "quality" and "sampling-factor" settings that were found
in the input file, if the input was in JPEG format. These settings are
also preserved if the input is a JPEG file and the output is a JNG
file.  If the colorspace of the output file differs from that of the
input file, the quality setting is preserved but the sampling-factors
are not.

.in 15
.in 15
.B "pcl:fit-to-page"
.in 20
 \fR
.in 20
If the pcl:fit-to-page flag is defined, then the printer is
requested to scale the image to fit the page size (width and/or
height).
.in 15
.in 15
.B "png:chunk-malloc-max=<value>"
.in 20
 \fR
.in 20
png:chunk-malloc-max specifies the maximum chunk size that libpng
will be allowed to read.  Libpng's default is normally 8,000,000
bytes. Very rarely, a valid PNG file may be encountered where the
error is reported "chunk data is too large".  In this case, the limit
may be increased using this option.  Take care when increasing this
limit since an excessively large limit could allow untrusted files to
use excessive memory.

.in 15
.in 15
.B "mng:maximum-loops=<value>"
.in 20
 \fR
.in 20
mng:maximum-loops specifies the maximum number of loops allowed to
be specified by a MNG LOOP chunk. Without an imposed limit, a MNG file
could request up to 2147483647 loops, which could run for a very long
time.  The current default limit is 512 loops.

.in 15
.in 15
.B "pdf:use-cropbox={true|false}"
.in 20
 \fR
.in 20
If the pdf:use-cropbox flag is set to \fBtrue\fP, then
Ghostscript is requested to apply the PDF crop box.

.in 15
.in 15
.B "pdf:stop-on-error={true|false}"
.in 20
 \fR
.in 20
If the pdf:stop-on-error flag is set to \fBtrue\fP, then
Ghostscript is requested to stop processing the PDF when the first
error is encountered.  Otherwise it will attempt to process all
requested pages.

.in 15
.in 15
.B "ps:imagemask"
.in 20
 \fR
.in 20
If the ps:imagemask flag is defined, the PS3 and EPS3 coders will
create Postscript files that render bilevel images with the Postscript
imagemask operator instead of the image operator.

.in 15
.in 15
.B "ptif:minimum-geometry=<geometry>"
.in 20
 \fR
.in 20
If the ptif:minimum-geometry key is defined, GraphicsMagick will
use it to determine the minimum frame size to output when writing a
pyramid TIFF file (a TIFF file containing a succession of reduced
versions of the first frame). The default minimum geometry is 32x32.

.in 15
.in 15
.B "tiff:alpha={unspecified|associated|unassociated}"
.in 20
 \fR
.in 20
Specify the TIFF alpha channel type when reading or writing TIFF files,
overriding the normal value. The default alpha channel type for new files
is unspecified alpha. Existing alpha settings are preserved when
converting from one TIFF file to another. When a TIFF file uses
associated alpha, the image pixels are pre-multiplied (i.e. altered) with
the alpha channel. Files with "associated" alpha appear as if they were
alpha composited on a black background when the matte channel is
disabled. If the unassociated alpha type is selected, then the alpha
channel is saved without altering the pixels. Photoshop recognizes
associated alpha as transparency information, if the file is saved with
unassociated alpha, the alpha information is loaded as an independent
channel.  Note that for many years, ImageMagick and GraphicsMagick marked
TIFF files as using associated alpha, without properly pre-multiplying
the pixels.

.in 15
.in 15
.B "tiff:fill-order={msb2lsb|lsb2msb}"
.in 20
 \fR
.in 20
If the tiff:fill-order key is defined, GraphicsMagick will use it to
determine the bit fill order used while writing TIFF files. The normal default
is "msb2lsb", which matches the native bit order of all modern CPUs. The
only exception to this is when Group3 or Group4 FAX compression is
requested since FAX machines send data in bit-reversed order and
therefore RFC 2301 recommends using reverse order.

.in 15
.in 15
.B "tiff:group-three-options=<value>"
.in 20
 \fR
.in 20
If the tiff:group-three-options key is defined, GraphicsMagick
will use it to set the group3 options tag when writing
group3-compressed TIFF.  Please see the TIFF specification for the
usage of this tag.  The default value is 4.

.in 15
.in 15
.B "tiff:ignore-tags=<tags>"
.in 20
 \fR
.in 20
If the tiff:ignore-tags key is defined, then it is used as a list
of comma-delimited integer TIFF tag values to ignore while reading the
TIFF file.  This is useful in order to be able to read files which
which otherwise fail to read due to problems with TIFF tags.  Note
that some TIFF tags are required in order to be able to read the image
data at all.

.in 15
.in 15
.B "tiff:report-warnings={false|true}"
.in 20
 \fR
.in 20
If the tiff:report-warnings key is defined and set to \fBtrue\fP,
then TIFF warnings are reported as a warning exception rather than as
a coder log message.  Such warnings are reported after the image has
been read or written.  Most TIFF warnings are benign but sometimes
they may help deduce problems with the TIFF file, or help detect that
the TIFF file requires a special application to read successfully due
to the use of proprietary or specialized extensions.

.in 15
.in 15
.B "tiff:sample-format={unsigned|ieeefp}"
.in 20
 \fR
.in 20
If the tiff:sample-format key is defined, GraphicsMagick will use it to
determine the sample format used while writing TIFF files. The default is
"unsigned". Specify "ieeefp" in order to write floating-point TIFF
files with float (32-bit) or double (64-bit) values. Use the
tiff:bits-per-sample define to determine the type of floating-point value
to use.

.in 15
.in 15
.B "tiff:max-sample-value=<value>"
.in 20
 \fR
.in 20
If the tiff:max-sample-value key is defined, GraphicsMagick will use the
assigned value as the maximum floating point value while reading or
writing IEEE floating point TIFFs. Otherwise the maximum value is 1.0 or
the value obtained from the file's SMaxSampleValue tag (if present). The
floating point data is currently not scanned in advance to determine a
best maximum sample value so if the range is not 1.0, or the
SMaxSampleValue tag is not present, it may be necessary to
(intelligently) use this parameter to properly read a file.

.in 15
.in 15
.B "tiff:min-sample-value=<value>"
.in 20
 \fR
.in 20
If the tiff:min-sample-value key is defined, GraphicsMagick will use
the assigned value as the minimum floating point value while reading or
writing IEEE floating point TIFFs. Otherwise the minimum value is 0.0 or
the value obtained from the file's SMinSampleValue tag (if present).

.in 15
.in 15
.B "tiff:bits-per-sample=<value>"
.in 20
 \fR
.in 20
If the tiff:bits-per-sample key is defined, GraphicsMagick will write
images with the specified bits per sample, overriding any existing depth
value. Value may be any in the range of 1 to 32, or 64 when the default
\'unsigned' format is written, or 16/32/24/64 if IEEEFP format is written.
Please note that the baseline TIFF 6.0 specification only requires
readers to handle certain powers of two, and the values to be handled
depend on the nature of the image (e.g. colormapped, grayscale, RGB, CMYK).

.in 15
.in 15
.B "tiff:samples-per-pixel=<value>"
.in 20
 \fR
.in 20
If the tiff:samples-per-pixel key is defined to a value, the TIFF coder
will write TIFF images with the defined samples per pixel, overriding any
value stored in the image. This option should not normally be used.

.in 15
.in 15
.B "tiff:rows-per-strip=<value>"
.in 20
 \fR
.in 20
Allows the user to specify the number of rows per TIFF strip.
Rounded up to a multiple of 16 when using JPEG compression. Ignored when
using tiles.

.in 15
.in 15
.B "tiff:strip-per-page=true"
.in 20
 \fR
.in 20
Requests that the image is written in a single TIFF strip. This is
normally the default when group3 or group4 compression is requested
within reasonable limits. Requesting a single strip for large images may
result in failure due to resource consumption in the writer or reader.

.in 15
.in 15
.B "tiff:tile"
.in 20
 \fR
.in 20
Enable writing tiled TIFF (rather than stripped) using the default tile
size. Tiled TIFF organizes the image as an array of smaller images
(tiles) in order to enable random access.

.in 15
.in 15
.B "tiff:tile-geometry=<width>x<height>"
.in 20
 \fR
.in 20
Specify the tile size to use while writing tiled TIFF. Width and
height should be a multiple of 16. If the value is not a multiple of 16,
then it will be rounded down. Enables tiled TIFF if it has not already
been enabled. GraphicsMagick does not use tiled storage internally so
tiles need to be converted back and forth from the internal
scanline-oriented storage to tile-oriented storage. Testing with typical
RGB images shows that useful square tile size values range from 128x128
to 1024x1024. Large images which require using a disk-based pixel cache
benefit from large tile sizes while images which fit in memory work well
with smaller tile sizes.

.in 15
.in 15
.B "tiff:tile-width=<width>"
.in 20
 \fR
.in 20
Specify the tile width to use while writing tiled TIFF. The tile height
is then defaulted to an appropriate size. Width should be a multiple of
16. If the value is not a multiple of 16, then it will be rounded down.
Enables tiled TIFF if it has not already been enabled.

.in 15
.in 15
.B "tiff:tile-height=<height>"
.in 20
 \fR
.in 20
Specify the tile height to use while writing tiled TIFF. The tile width
is then defaulted to an appropriate size. Height should be a multiple of
16. If the value is not a multiple of 16, then it will be rounded down.
Enables tiled TIFF if it has not already been enabled.

.in 15
.in 15
.B "tiff:webp-lossless={TRUE|FALSE}"
.in 20
 \fR
.in 20
Specify a value of \fBTRUE\fP to enable lossless mode while
writing WebP-compressed TIFF files. The WebP \fBwebp:lossless\fP
option may also be used.  The quality factor set by the
\fB-quality\fP option may be used to influence the level of effort
expended while compressing.

.in 15
.in 15
.B "tiff:zstd-compress-level=<value>"
.in 20
 \fR
.in 20
Specify the compression level to use while writing Zstd-compressed
TIFF files. The valid range is 1 to 22. If this define is not
specified, then the 'quality' value is used such that the default
quality setting of 75 is translated to a compress level of 9 such that
\'quality' has a useful range of 10-184 if used for this purpose.

.in 15
.in 15
.B "webp:lossless={true|false}"
.in 20
 \fR
.in 20
Enable lossless encoding.

.in 15
.in 15
.B "webp:method={0-6}"
.in 20
 \fR
.in 20
Quality/speed trade-off.

.in 15
.in 15
.B "webp:image-hint={default,graph,photo,picture}"
.in 20
 \fR
.in 20
Hint for image type.

.in 15
.in 15
.B "webp:target-size=<integer>"
.in 20
 \fR
.in 20
Target size in bytes.

.in 15
.in 15
.B "webp:target-psnr=<float>"
.in 20
 \fR
.in 20
Minimal distortion to try to achieve.

.in 15
.in 15
.B "webp:segments={1-4}"
.in 20
 \fR
.in 20
Maximum number of segments to use.

.in 15
.in 15
.B "webp:sns-strength={0-100}"
.in 20
 \fR
.in 20
Spatial Noise Shaping.

.in 15
.in 15
.B "webp:filter-strength={0-100}"
.in 20
 \fR
.in 20
Filter strength.

.in 15
.in 15
.B "webp:filter-sharpness={0-7}"
.in 20
 \fR
.in 20
Filter sharpness.

.in 15
.in 15
.B "webp:filter-type={0,1}"
.in 20
 \fR
.in 20
Filtering type. 0 = simple, 1 = strong (only used if
filter-strength > 0 or autofilter is enabled).

.in 15
.in 15
.B "webp:auto-filter={true|false}"
.in 20
 \fR
.in 20
Auto adjust filter's strength.

.in 15
.in 15
.B "webp:alpha-compression=<integer>"
.in 20
 \fR
.in 20
Algorithm for encoding the alpha plane (0 = none, 1 = compressed
with WebP lossless). Default is 1.

.in 15
.in 15
.B "webp:alpha-filtering=<integer>"
.in 20
 \fR
.in 20
Predictive filtering method for alpha plane. 0: none, 1: fast, 2:
best. Default is 1.

.in 15
.in 15
.B "webp:alpha-quality={0-100}"
.in 20
 \fR
.in 20
Between 0 (smallest size) and 100 (lossless). Default is 100.

.in 15
.in 15
.B "webp:pass=[1..10]"
.in 20
 \fR
.in 20
Number of entropy-analysis passes.

.in 15
.in 15
.B "webp:show-compressed={true|false}"
.in 20
 \fR
.in 20
Export the compressed picture back.  In-loop filtering is not
applied.

.in 15
.in 15
.B "webp:preprocessing=[0,1,2]"
.in 20
 \fR
.in 20
0=none, 1=segment-smooth, 2=pseudo-random dithering

.in 15
.in 15
.B "webp:partitions=[0-3]"
.in 20
 \fR
.in 20
log2(number of token partitions) in [0..3].  Default is 0 for
easier progressive decoding.

.in 15
.in 15
.B "webp:partition-limit={0-100}"
.in 20
 \fR
.in 20
Quality degradation allowed to fit the 512k limit on prediction
modes coding (0: no degradation, 100: maximum possible
degradation).

.in 15
.in 15
.B "webp:emulate-jpeg-size={true|false}"
.in 20
 \fR
.in 20
If true, compression parameters will be remapped to better match
the expected output size from JPEG compression. Generally, the output
size will be similar but the degradation will be lower.

.in 15
.in 15
.B "webp:thread-level=<integer>"
.in 20
 \fR
.in 20
If non-zero, try and use multi-threaded encoding.

.in 15
.in 15
.B "webp:low-memory={true|false}"
.in 20
 \fR
.in 20
If set, reduce memory usage (but increase CPU use)

.in 15
.in 15
.B "webp:use-sharp-yuv={true|false}"
.in 20
 \fR
.in 20
If set, if needed, use sharp (and slow) RGB->YUV conversion

.in 15



For example, to create a postscript file that will render only the black
pixels of a bilevel image, use:

.nf
    gm convert bilevel.tif -define ps:imagemask eps3:stencil.ps
.fi
.TP
.B "-delay \fI<1/100ths of a second>"\fP
\fRdisplay the next image after pausing

This option is useful for regulating the animation of image sequences
\fIDelay/100\fP seconds must expire before the display
of the next image. The default is no delay between each showing of the
image sequence. The maximum delay is 65535.

You can specify a delay range (e.g. \fI-delay 10-500\fP) which sets the
minimum and maximum delay.
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
This option specifies the image resolution to store while encoding a
raster image or the canvas resolution while rendering (reading) vector
formats such as Postscript, PDF, WMF, and SVG into a raster image. Image
resolution provides the unit of measure to apply when rendering to an
output device or raster image. The default unit of measure is in dots
per inch (DPI). The \fB-units\fP option may be used to select dots per
centimeter instead.
 The default resolution is 72 dots per inch, which is equivalent to
one point per pixel (Macintosh and Postscript standard). Computer
screens are normally 72 or 96 dots per inch while printers typically
support 150, 300, 600, or 1200 dots per inch. To determine the
resolution of your display, use a ruler to measure the width of your
screen in inches, and divide by the number of horizontal pixels (1024 on
a 1024x768 display).
If the file format supports it, this option may be used to update
the stored image resolution. Note that Photoshop stores and obtains
image resolution from a proprietary embedded profile. If this profile is
not stripped from the image, then Photoshop will continue to treat the
image using its former resolution, ignoring the image resolution
specified in the standard file header.
The density option is an attribute and does not alter the underlying
raster image. It may be used to adjust the rendered size for desktop
publishing purposes by adjusting the scale applied to the pixels. To
resize the image so that it is the same size at a different resolution,
use the \fB-resample\fP option.
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image

This is the number of bits of color to preserve in the image. Any value
between 1 and \fBQuantumDepth\fP (build option) may be specified,
although 8 or 16 are the most common values. Use this option to specify
the depth of raw images whose depth is unknown such as GRAY, RGB, or
CMYK, or to change the depth of any image after it has been read.
The depth option is applied to the pixels immediately so it may be
used as a form of simple compression by discarding the least significant
bits. Reducing the depth in advance may speed up color quantization, and
help create smaller file sizes when using a compression algorithm like
LZW or ZIP.
.TP
.B "-descend"
\fRobtain image by descending window hierarchy
.TP
.B "-despeckle"
\fRreduce the speckles within an image
.TP
.B "-displace \fI<horizontal scale>x<vertical scale>"\fP
\fRshift image pixels as defined by a displacement map

With this option, \fIcomposite image\fP is used as a displacement map.  Black,
within the displacement map, is a maximum positive displacement.  White is a
maximum negative displacement and middle gray is neutral.  The displacement
is scaled to determine the pixel shift.  By default, the displacement applies
in both the horizontal and vertical directions.  However, if you specify
\fImask\fP, \fIcomposite image\fP is the horizontal X displacement and
\fImask\fP the vertical Y displacement.
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact

This option is used with convert for
obtaining image or font from this X server.  See \fIX(1)\fP.
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method

The Disposal Method indicates the way in which the graphic is to
be treated after being displayed.

Here are the valid methods:

.nf
    Undefined       No disposal specified.
    None            Do not dispose between frames.
    Background      Overwrite the image area with
                    the background color.
    Previous        Overwrite the image area with
                    what was there prior to rendering
                    the image.
.fi
.TP
.B "-dissolve \fI<percent>"\fP
\fRdissolve an image into another by the given percent

The opacity of the composite image is multiplied by the given percent,
then it is composited over the main image.
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image

The basic strategy of dithering is to trade intensity resolution for spatial
resolution by averaging the intensities of several neighboring pixels.
Images which suffer from severe contouring when reducing colors can be
improved with this option.

The \fB-colors\fP or \fB-monochrome\fP option is required for this option
to take effect.

Use \fB+dither\fP to turn off dithering and to render PostScript
without text or graphic aliasing. Disabling dithering often (but not
always) leads to decreased processing time.
.TP
.B "-draw \fI<string>"\fP
\fRannotate an image with one or more graphic primitives

Use this option to annotate an image with one or more graphic primitives.
The primitives include shapes, text, transformations,
and pixel operations.  The shape primitives are

.nf
     point           x,y
     line            x0,y0 x1,y1
     rectangle       x0,y0 x1,y1
     roundRectangle  x0,y0 x1,y1 wc,hc
     arc             x0,y0 x1,y1 a0,a1
     ellipse         x0,y0 rx,ry a0,a1
     circle          x0,y0 x1,y1
     polyline        x0,y0  ...  xn,yn
     polygon         x0,y0  ...  xn,yn
     Bezier          x0,y0  ...  xn,yn
     path            path specification
     image           operator x0,y0 w,h filename
.fi

The text primitive is

.nf
     text            x0,y0 string
.fi

The text gravity primitive is

.nf
     gravity         NorthWest, North, NorthEast, West, Center,
                     East, SouthWest, South, or SouthEast
.fi

The text gravity primitive only affects the placement of text and
does not interact with the other primitives.  It is equivalent to
using the \fB-gravity\fP commandline option, except that it is
limited in scope to the \fB-draw\fP option in which it appears.

The transformation primitives are

.nf
     rotate          degrees
     translate       dx,dy
     scale           sx,sy
     skewX           degrees
     skewY           degrees
.fi

The pixel operation primitives are

.nf
     color           x0,y0 method
     matte           x0,y0 method
.fi

The shape primitives are drawn in the color specified in the preceding
\fB-stroke\fP option. Except for the \fBline\fP and \fBpoint\fP
primitives, they are filled with the color specified in the preceding
\fB-fill\fP option.  For unfilled shapes, use -fill none.

\fBPoint\fP requires a single coordinate.

\fBLine\fP requires a start and end coordinate.

\fBRectangle\fP
expects an upper left and lower right coordinate.

\fBRoundRectangle\fP has the upper left and lower right coordinates
and the width and height of the corners.

\fBCircle\fP has a center coordinate and a coordinate for
the outer edge.

Use \fBArc\fP to inscribe an elliptical arc within
a rectangle.  Arcs require a start and end point as well as the degree
of rotation (e.g. 130,30 200,100 45,90).

Use \fBEllipse\fP to draw a partial ellipse
centered at the given point with the x-axis and y-axis radius
and start and end of arc in degrees (e.g. 100,100 100,150 0,360).

Finally, \fBpolyline\fP and \fBpolygon\fP require
three or more coordinates to define its boundaries.
Coordinates are integers separated by an optional comma.  For example,
to define a circle centered at 100,100
that extends to 150,150 use:

.nf
     -draw 'circle 100,100 150,150'
.fi

\fBPaths\fP
(See Paths)
represent an outline of an object which is defined in terms of
moveto (set a new current point), lineto (draw a straight line),
curveto (draw a curve using a cubic Bezier), arc (elliptical or
circular arc) and closepath (close the current shape by drawing a line
to the last moveto) elements. Compound paths (i.e., a path with
subpaths, each consisting of a single moveto followed by one or more
line or curve operations) are possible to allow effects such as
"donut holes" in objects.

Use \fBimage\fP to composite an image with another image. Follow the
image keyword with the composite operator, image location, image size,
and filename:

.nf
     -draw 'image Over 100,100 225,225 image.jpg'
.fi

You can use 0,0 for the image size, which means to use the actual
dimensions found in the image header. Otherwise, it will
be scaled to the given dimensions.
See \fB-compose\fP for a description of the composite operators.

Use \fBtext\fP to annotate an image with text. Follow the text
coordinates with a string. If the string has embedded spaces, enclose it
in single or double quotes. Optionally you can include the image
filename, type, width, height, or other image attribute by embedding
special format character. See \fB-comment\fP for details.

For example,


.nf
     -draw 'text 100,100 "%m:%f %wx%h"'


annotates the image with MIFF:bird.miff 512x480 for an image titled
bird.miff
and whose width is 512 and height is 480.

If the first character of \fIstring\fP is \fI@\fP, the text is read
from a file titled by the remaining characters in the string.  Please
note that if the string comes from an untrusted source that it should
be sanitized before use (a security risk).

\fBRotate\fP rotates subsequent shape primitives and text primitives about
the origin of the main image. If the \fB-region\fP option precedes the
\fB-draw\fP option, the origin for transformations is the upper left
corner of the region.

\fBTranslate\fP translates them.

\fBScale\fP scales them.

\fBSkewX\fP and \fBSkewY\fP skew them with respect to the origin of
the main image or the region.

The transformations modify the current affine matrix, which is initialized
from the initial affine matrix defined by the \fB-affine\fP option.
Transformations are cumulative within the \fB-draw\fP option.
The initial affine matrix is not affected; that matrix is only changed by the
appearance of another \fB-affine\fP option.  If another \fB-draw\fP
option appears, the current affine matrix is reinitialized from
the initial affine matrix.

Use \fBcolor\fP to change the color of a pixel to the fill color (see
\fB-fill\fP). Follow the pixel coordinate
with a method:

.nf
     point
     replace
     floodfill
     filltoborder
     reset
.fi

Consider the target pixel as that specified by your coordinate. The
\fBpoint\fP
method recolors the target pixel. The \fBreplace\fP method recolors any
pixel that matches the color of the target pixel.
\fBFloodfill\fP recolors
any pixel that matches the color of the target pixel and is a neighbor,
whereas \fBfilltoborder\fP recolors any neighbor pixel that is not the
border color. Finally, \fBreset\fP recolors all pixels.

Use \fBmatte\fP to the change the pixel matte value to transparent. Follow
the pixel coordinate with a method (see the \fBcolor\fP primitive for
a description of methods). The \fBpoint\fP method changes the matte value
of the target pixel. The \fBreplace\fP method changes the matte value
of any pixel that matches the color of the target pixel. \fBFloodfill\fP
changes the matte value of any pixel that matches the color of the target
pixel and is a neighbor, whereas
\fBfilltoborder\fP changes the matte
value of any neighbor pixel that is not the border color (\fB-bordercolor\fP).
Finally \fBreset\fP changes the matte value of all pixels.

You can set the primitive color, font, and font bounding box
color with
\fB-fill\fP, \fB-font\fP, and \fB-box\fP respectively. Options
are processed in command line order so be sure to use these
options \fIbefore\fP the \fB-draw\fP option.
.TP
.B "-edge \fI<radius>"\fP
\fRdetect edges within an image
.TP
.B "-emboss \fI<radius>"\fP
\fRemboss an image
.TP
.B "-encoding \fI<type>"\fP
\fRspecify the text encoding

Choose from \fIAdobeCustom, AdobeExpert, AdobeStandard, AppleRoman,
BIG5, GB2312, Latin 2, None, SJIScode, Symbol, Unicode, Wansung.\fP
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image

\fIMSB\fP indicates big-endian (e.g. SPARC, Motorola 68K) while
\fILSB\fP indicates little-endian (e.g. Intel 'x86, VAX) byte
ordering.  \fINative\fP indicates to use the normal ordering for the
current CPU.  This option currently only influences the CMYK, DPX,
GRAY, RGB, and TIFF, formats.

Use \fB+endian\fP to revert to unspecified endianness.
.TP
.B "-enhance"
\fRapply a digital filter to enhance a noisy image
.TP
.B "-equalize"
\fRperform histogram equalization to the image
.TP
.B "-extent \fI<width>x<height>{+-}<x>{+-}<y>"\fP
\fRcomposite image on background color canvas image

This option composites the image on a new background color
(\fB-background\fP) canvas image of size <width>x<height>. The
existing image content is composited at the position specified by
geometry x and y offset and/or desired gravity (\fB-gravity\fP) using
the current image compose (\fB-compose\fP) method.  Image content
which falls outside the bounds of the new image dimensions is
discarded.

For example, this command creates a thumbnail of an image, and centers
it on a red color backdrop image, offsetting the canvas ten pixels to
the left and five pixels up, with respect to the thumbnail:

.nf
    gm convert infile.jpg -thumbnail 120x80 -background red -gravity center \\
              -extent 140x100-10-5 outfile.jpg
.fi

This command reduces or expands a JPEG image to fit on an 800x600
display: 

.nf
    gm convert -size 800x600 input.jpg \\
              -resize 800x600 -background black \\
              -compose Copy -gravity center \\
              -extent 800x600 \\
              -quality 92 output.jpg
.fi

If the aspect ratio of the input image isn't exactly 4:3, then the
image is centered on an 800x600 black canvas. 
.TP
.B "-file \fI<filename>"\fP
\fRwrite annotated difference image to file

If \fB-file\fP is specified, then an annotated difference image is
generated and written to the specified file. Pixels which differ between
the \fBreference\fP and \fBcompare\fP images are modified from those in
the \fBcompare\fP image so that the changed pixels become more obvious.
Some images may require use of an alternative highlight style (see
\fB-highlight-style\fP) or highlight color (see \fB-highlight-color\fP)
before the changes are obvious.
.TP
.B "-fill \fI<color>"\fP
\fRcolor to use when filling a graphic primitive

Colors are represented in GraphicsMagick in the same form used by SVG. Use "gm convert -list color" to list named colors:

.nf
    name               (named color)
    #RGB               (hex numbers, 4 bits each)
    #RRGGBB            (8 bits each)
    #RRRGGGBBB         (12 bits each)
    #RRRRGGGGBBBB      (16 bits each)
    #RGBA              (4 bits each)
    #RRGGBBAA          (8 bits each)
    #RRRGGGBBBAAA      (12 bits each)
    #RRRRGGGGBBBBAAAA  (16 bits each)
    rgb(r,g,b)         (r,g,b are decimal numbers)
    rgba(r,g,b,a)      (r,g,b,a are decimal numbers)
.fi

Enclose the color specification in quotation marks to prevent the "#"
or the parentheses from being interpreted by your shell.

For example,

.nf
    gm convert -fill blue ...
    gm convert -fill "#ddddff" ...
    gm convert -fill "rgb(65000,65000,65535)" ...
.fi

The shorter forms are scaled up, if necessary by replication.  For example, 
#3af, #33aaff, and #3333aaaaffff are all equivalent.

See \fB-draw\fP for further details.
.TP
.B "-filter \fI<type>"\fP
\fRuse this type of filter when resizing an image

Use this option to affect the resizing operation of an image (see
\fB-geometry\fP).
Choose from these filters (ordered by approximate increasing CPU
time):

.nf
     Point
     Box
     Triangle
     Hermite
     Hanning
     Hamming
     Blackman
     Gaussian
     Quadratic
     Cubic
     Catrom
     Mitchell
     Lanczos
     Bessel
     Sinc
.fi

The default filter is automatically selected to provide the best quality
while consuming a reasonable amount of time. The \fBMitchell\fP filter
is used if the image supports a palette, supports a matte channel, or is
being enlarged, otherwise the \fBLanczos\fP filter is used.
.TP
.B "-flatten"
\fRflatten a sequence of images

In some file formats (e.g. Photoshop's PSD) complex images may be
represented by "layers" (independent images) which must be composited
in order to obtain the final rendition.  The \fB-flatten\fP option
accomplishes this composition.  The sequence of images is replaced by
a single image created by compositing each image in turn, while
respecting composition operators and page offsets.  While
\fB-flatten\fP is immediately useful for eliminating layers, it is
also useful as a general-purpose composition tool.

The sequence of images is terminated by the appearance of any option.
If the \fB-flatten\fP option appears after all of the input images,
all images are flattened.  Also see \fB-mosaic\fP which is similar to
\fB-flatten\fP except that it adds a suitably-sized canvas base
image.

For example, this composites an image on top of a 640x400 transparent
black canvas image:

.nf
    gm convert -size 640x300 xc:transparent \\
              -compose over -page +0-100 \\
              frame.png -flatten output.png
.fi

and this flattens a Photoshop PSD file:

.nf
    gm convert input.psd -flatten output.png
.fi
.TP
.B "-flip"
\fRcreate a "mirror image"

reflect the scanlines in the vertical direction.
.TP
.B "-flop"
\fRcreate a "mirror image"

reflect the scanlines in the horizontal direction.
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text

You can tag a font to specify whether it is a PostScript, TrueType, or X11
font.  For example, Arial.ttf is a TrueType font, ps:helvetica
is PostScript, and x:fixed is X11.
.TP
.B "-foreground \fI<color>"\fP
\fRdefine the foreground color

The color is specified using the format described under the \fB-fill\fP
option.
.TP
.B "-format \fI<type>"\fP
\fRthe image format type

When used with the \fBmogrify\fP utility,
this option will convert any image to the image format you specify.
See \fIGraphicsMagick(1)\fP for a list of image format types supported by
\fBGraphicsMagick\fP, or see the output of 'gm -list format'.

By default the file is written to its original name.  However, if the
filename extension matches a supported format, the extension is replaced
with the image format type specified with \fB-format\fP.  For example,
if you specify \fItiff\fP as the format type and the input image
filename is \fIimage.gif\fP, the output image filename becomes
\fIimage.tiff\fP.
.TP
.B "-format \fI<string>"\fP
\fRoutput formatted image characteristics

When used with the \fBidentify\fP utility, or the \fBconvert\fP
utility with output written to the 'info:-' file specification, use
this option to print information about the image in a format of your
choosing.  You can include the image filename, type, width, height,
Exif data, or other image attributes by embedding special format
characters:

.nf
     %b   file size
     %c   comment
     %d   directory
     %e   filename extension
     %f   filename
     %g   page dimensions and offsets
     %h   height
     %i   input filename
     %k   number of unique colors
     %l   label
     %m   magick
     %n   number of scenes
     %o   output filename
     %p   page number
     %q   image bit depth
     %r   image type description
     %s   scene number
     %t   top of filename
     %u   unique temporary filename
     %w   width
     %x   horizontal resolution
     %y   vertical resolution
     %A   transparency supported
     %C   compression type
     %D   GIF disposal method
     %G   Original width and height
     %H   page height
     %M   original filename specification
     %O   page offset (x,y)
     %P   page dimensions (width,height)
     %Q   compression quality
     %T   time delay (in centi-seconds)
     %U   resolution units
     %W   page width
     %X   page horizontal offset (x)
     %Y   page vertical offset (y)
     %@   trim bounding box
     %#   signature
     \\n   newline
     \\r   carriage return
     %%   %
.fi

For example,

.nf
     -format "%m:%f %wx%h"
.fi

displays \fBMIFF:bird.miff 512x480\fP for an image
titled \fBbird.miff\fP and whose width is 512 and height is 480.

If the first character of \fIstring\fP is \fB@\fP, the format is
read from a file titled by the remaining characters in the string.
Please note that if the string comes from an untrusted source that it
should be sanitized before use since this may be used to incorporate
any readable file on the system (a security risk).

The values of image type (\fB%r\fP) which may be returned include:

.nf
     Bilevel
     Grayscale
     GrayscaleMatte
     Palette
     PaletteMatte
     TrueColor
     TrueColorMatte
     ColorSeparation
     ColorSeparationMatte
     Optimize
.fi

You can also use the following special formatting syntax to print Exif
information contained in the file:

.nf
     %[EXIF:<tag>]
.fi

Where "<tag>" may be one of the following:

.nf
     *  (print all Exif tags, in keyword=data format)
     !  (print all Exif tags, in tag_number format)
     #hhhh (print data for Exif tag #hhhh)
     ImageWidth
     ImageLength
     BitsPerSample
     Compression
     PhotometricInterpretation
     FillOrder
     DocumentName
     ImageDescription
     Make
     Model
     StripOffsets
     Orientation
     SamplesPerPixel
     RowsPerStrip
     StripByteCounts
     XResolution
     YResolution
     PlanarConfiguration
     ResolutionUnit
     TransferFunction
     Software
     DateTime
     Artist
     WhitePoint
     PrimaryChromaticities
     TransferRange
     JPEGProc
     JPEGInterchangeFormat
     JPEGInterchangeFormatLength
     YCbCrCoefficients
     YCbCrSubSampling
     YCbCrPositioning
     ReferenceBlackWhite
     CFARepeatPatternDim
     CFAPattern
     BatteryLevel
     Copyright
     ExposureTime
     FNumber
     IPTC/NAA
     ExifOffset
     InterColorProfile
     ExposureProgram
     SpectralSensitivity
     GPSInfo
     ISOSpeedRatings
     OECF
     ExifVersion
     DateTimeOriginal
     DateTimeDigitized
     ComponentsConfiguration
     CompressedBitsPerPixel
     ShutterSpeedValue
     ApertureValue
     BrightnessValue
     ExposureBiasValue
     MaxApertureValue
     SubjectDistance
     MeteringMode
     LightSource
     Flash
     FocalLength
     MakerNote
     UserComment
     SubSecTime
     SubSecTimeOriginal
     SubSecTimeDigitized
     FlashPixVersion
     ColorSpace
     ExifImageWidth
     ExifImageLength
     InteroperabilityOffset
     FlashEnergy
     SpatialFrequencyResponse
     FocalPlaneXResolution
     FocalPlaneYResolution
     FocalPlaneResolutionUnit
     SubjectLocation
     ExposureIndex
     SensingMethod
     FileSource
     SceneType
.fi

JPEG specific information (from reading a JPEG file) may be obtained
like this:

.nf
     %[JPEG-<tag>]
.fi

Where "<tag>" may be one of the following:

.nf
     *                 (all JPEG-related tags, in
                        keyword=data format)
     Quality           IJG JPEG "quality" estimate
     Colorspace        JPEG colorspace numeric ID
     Colorspace-Name   JPEG colorspace name
     Sampling-factors  JPEG sampling factors
.fi

Please note that JPEG has no notion of "quality" and that the quality
metric used by, and estimated by the software is based on the quality
metric established by IJG JPEG 6b.  Other encoders (e.g. that used by
Adobe Photoshop) use different encoding metrics.

Surround the format specification with quotation marks to prevent your shell
from misinterpreting any spaces and square brackets.
.TP
.B "-frame \fI<width>x<height>+<outer bevel width>+<inner bevel width>"\fP
\fRsurround the image with an ornamental border

See \fB-geometry\fP for details about the geometry
specification.  The \fB-frame\fP option is not affected by the
\fB-gravity\fP option.

The color of the border is specified with the \fB-mattecolor\fP
command line option.
.TP
.B "-frame"
\fRinclude the X window frame in the imported image
.TP
.B "-fuzz \fI<distance>{%}"\fP
\fRcolors within this Euclidean distance are considered equal

A number of algorithms search for a target color. By default the color
must be exact. Use this option to match colors that are close (in
Euclidean distance) to the target color in RGB 3D space. For example,
if you want to automatically trim the edges of an image with
\fB-trim\fP but the image was scanned and the target background color
may differ by a small amount. This option can account for these
differences.

The \fIdistance\fP can be in absolute intensity units or, by appending
\fI"%"\fP, as a percentage of the maximum possible intensity (255,
65535, or 4294967295).
.TP
.B "-gamma \fI<value>"\fP
\fRlevel of gamma correction

The same color image displayed on two different workstations may look
different due to differences in the display monitor. Use gamma
correction to adjust for this color difference. Reasonable values extend
from \fB0.8\fP to \fB2.3\fP. Gamma less than 1.0 darkens the image and
gamma greater than 1.0 lightens it. Large adjustments to image gamma may
result in the loss of some image information if the pixel quantum size
is only eight bits (quantum range 0 to 255).

You can apply separate gamma values to the red, green, and blue channels
of the image with a gamma value list delimited with slashes
(e.g., \fB1.7\fP/\fB2.3\fP/\fB1.2\fP).

Use \fB+gamma\fP \fIvalue\fP
to set the image gamma level without actually adjusting
the image pixels. This option is useful if the image is of a known gamma
but not set as an image attribute (e.g. PNG images).
.TP
.B "-gaussian \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator

Use the given radius and standard deviation (sigma).
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.

The \fB-geometry\fP option is used for a number of different
purposes, depending on the utility it is used with.

For the X11 commands ('animate', 'display', and 'import'), it
specifies the preferred size and location of the Image window.  By
default, the window size is the image size and the location is chosen
by you (or your window manager) when it is mapped.
 For the 'import', 'convert', 'mogrify' utility commands it may be
used to specify the desired size when resizing an image.  In this
case, symbols representing resize options may be appended to the
geometry string to influence how the resize request is treated.

See later notes corresponding to usage by particular commands.  The
following notes apply to when \fB-geometry\fP is used to express a
resize request, taking into account the current properties of the
image.

By default, the width and height are maximum values. That is, the
image is expanded or contracted to fit the width and height value
while maintaining the aspect ratio of the image.

Append a ^ to the geometry so that the image aspect ratio is
maintained when the image is resized, but the resulting width or
height are treated as minimum values rather than maximum values.

Append a ! (exclamation point) to the geometry to force the image size to
exactly the size you specify. For example, if you specify
640x480! the image width is set to 640 pixels and height to
480.

If only the width is specified, without the trailing 'x', then height
is set to width (e.g., -geometry 100 is the same as
-geometry 100x100).  If only the width is specified but with
the trailing 'x', then width assumes the value and the height is
chosen to maintain the aspect ratio of the image.  Similarly, if only
the height is specified prefixed by 'x' (e.g., -geometry
x256), the width is chosen to maintain the aspect ratio.

To specify a percentage width or height instead, append %. The image size
is multiplied by the width and height percentages to obtain the final image
dimensions. To increase the size of an image, use a value greater than
100 (e.g. 125%). To decrease an image's size, use a percentage less than
100.

Use @ to specify the maximum area in pixels of an image.

Use > to change the dimensions of the image \fIonly\fP if
its width or height exceeds the geometry specification. < resizes
the image \fIonly\fP if both of its dimensions are less than the geometry
specification. For example,
if you specify '640x480>' and the image size is 256x256, the image
size does not change. However, if the image is 512x512 or 1024x1024, it is
resized to 480x480.  Enclose the geometry specification in quotation marks to
prevent the < or > from being interpreted by your shell
as a file redirection.

When used with \fIanimate\fP and \fIdisplay\fP, offsets are handled in
the same manner as in \fIX(1)\fP and the \fB-gravity\fP option is not used.
If the \fIx\fP is negative, the offset is measured leftward
from the right edge of the
screen to the right edge of the image being displayed.
Similarly, negative \fIy\fP is measured between the bottom edges.  The
offsets are not affected by "%"; they are always measured in pixels.

When used as a \fIcomposite\fP option, \fB-geometry\fP
gives the dimensions of the image and its location with respect
to the composite image.  If the \fB-gravity\fP option is present
with \fINorthEast, East,\fP or \fISouthEast\fP gravity, the \fIx\fP
represents the distance from the right edge of the image to the right edge of
the composite image.  Similarly, if the \fB-gravity\fP option is present
with \fISouthWest, South,\fP or \fISouthEast\fP gravity, \fIy\fP
is measured between the bottom edges. Accordingly, a positive offset will
never point in the direction outside of the image.  The
offsets are not affected by "%"; they are always measured in pixels.
To specify the dimensions of the composite image, use the \fB-resize\fP
option.

When used as a \fIconvert\fP, \fIimport\fP or \fImogrify\fP option,
\fB-geometry\fP is synonymous with \fB-resize\fP and
specifies the size of the output image.  The offsets, if present, are ignored.

When used as a \fImontage\fP option, \fB-geometry\fP specifies the image
size and border size for each tile; default is 256x256+0+0.  Negative
offsets (border dimensions) are meaningless.  The \fB-gravity\fP
option affects the placement of the image within the tile; the default
gravity for this purpose is \fICenter\fP.  If the "%" sign appears in
the geometry specification, the tile size is the specified percentage of
the original dimensions of the first tile.
To specify the dimensions of the montage, use the \fB-resize\fP
option.
.TP
.B "-gravity \fI<type>"\fP
\fRdirection primitive  gravitates to when annotating the image.

Choices are: NorthWest, North,
NorthEast, West, Center, East, SouthWest, South, SouthEast.

The direction you choose specifies where to position the text 
when annotating
the image. For example \fICenter\fP gravity forces the text to be centered
within the image. By default, the image gravity is \fINorthWest\fP.
See \fB-draw\fP for more details about graphic primitives.  Only the
text primitive is affected by the \fB-gravity\fP option.

The \fB-gravity\fP option is also used in concert with the \fB-geometry\fP
option and other options that take \fB<geometry>\fP as a parameter, such
as the \fB-crop\fP option.  See \fB-geometry\fP for details of how the
\fB-gravity\fP option interacts with the
\fB<x>\fP and \fB<y>\fP parameters of a geometry
specification.

When used as an option to \fIcomposite\fP, \fB-gravity\fP
gives the direction that the image gravitates within the composite.

When used as an option to \fImontage\fP, \fB-gravity\fP gives the direction
that an image gravitates within a tile.  The default gravity is \fICenter\fP
for this purpose.
.TP
.B "-green-primary \fI<x>,<y>"\fP
\fRgreen chromaticity primary point
.TP
.B "-hald-clut \fI<clut>"\fP
\fRapply a Hald CLUT to the image

A Hald CLUT ("Color Look-Up Table") is a special square color image
which contains a look-up table for red, green, and blue.  The size of
the Hald CLUT image is determined by its order.  The width (and
height) of a Hald CLUT is the cube of the order.  For example, a Hald
CLUT of order 8 is 512x512 pixels (262,144 colors) and of order 16 is
4096x4096 (16,777,216 colors).  A special CLUT is the identity CLUT
which which causes no change to the input image.  In order to use the
Hald CLUT, one takes an identity CLUT and adjusts its colors in some
way.  The modified CLUT can then be used to transform any number of
images in an identical way.

GraphicsMagick contains a built-in identity CLUT generator via the
\fBIDENTITY\fP coder.  For example reading from the file name
\fPIDENTITY:8\fP returns an identity CLUT of order 8.  Typical Hald
CLUT identity images have an order of between 8 and 16.  The default
order for the \fBIDENTITY\fP CLUT generator is 8.  Interpolation is
used so it is not usually necessary for CLUT images to be very large.
The PNG file format is ideal for storing Hald CLUT images because it
compresses them very well.
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-highlight-color \fI<color>"\fP
\fRpixel annotation color

Specifies the color to use when annotating difference pixels.
.TP
.B "-highlight-style \fI<style>"\fP
\fRpixel annotation style

Specifies the pixel difference annotation style used to draw attention to
changed pixels. May be one of \fBAssign\fP, \fBThreshold\fP,
\fBTint\fP, or \fBXOR\fP; where \fBAssign\fP replaces the pixel with
the highlight color (see \fB-highlight-color\fP), \fBThreshold\fP
replaces the pixel with black or white based on the difference in
intensity, \fBTint\fP alpha tints the pixel with the highlight color,
and \fBXOR\fP does an XOR between the pixel and the highlight color.
.TP
.B "-iconGeometry \fI<geometry>"\fP
\fRspecify the icon geometry

Offsets, if present in the geometry specification, are handled in
the same manner as the \fB-geometry\fP option, using X11 style to handle
negative offsets.
.TP
.B "-iconic"
\fRiconic animation
.TP
.B "-immutable"
\fRmake image immutable
.TP
.B "-implode \fI<factor>"\fP
\fRimplode image pixels about the center
.TP
.B "-intent \fI<type>"\fP
\fRuse this type of rendering intent when managing the image color

Use this option to affect the the color management operation of an image (see
\fB-profile\fP).
Choose from these intents:
\fBAbsolute, Perceptual, Relative, Saturation\fP.

The default intent is undefined.
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme

Choices are: \fBNone, Line, Plane,\fP
or \fBPartition\fP. The default is \fBNone\fP.

This option is used to specify the type of interlacing scheme for raw image
formats such as \fBRGB\fP or \fBYUV\fP.
\fBNone\fP means do not interlace
(RGBRGBRGBRGBRGBRGB...),

\fBLine\fP uses scanline interlacing
(RRR...GGG...BBB...RRR...GGG...BBB...),
and
\fBPlane\fP uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).

\fBPartition\fP
is like plane except the different planes are saved to individual files
(e.g. image.R, image.G, and image.B).

Use \fBLine\fP to create an \fBinterlaced PNG\fP or \fB GIF\fP or
\fBprogressive JPEG\fP image.
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image

Use this option to assign a specific label to the image, when writing
to an image format that supports labels, such as TIFF, PNG, MIFF, or
PostScript. You can include the the image filename, type, width, height,
or other image attribute by embedding special format character.  A label
is not drawn on the image, but is embedded in the image datastream via
a "Label" tag or similar mechanism.  If you want the
label to be visible on the image itself, use the \fB-draw\fP option.
See \fB-comment\fP for details.

For example,

.nf
     -label "%m:%f %wx%h"
.fi

produces an image label of \fBMIFF:bird.miff 512x480\fP for an image titled
\fBbird.miff\fP
and whose width is 512 and height is 480.

If the first character of \fIstring\fP is \fI@\fP, the image label
is read from a file titled by the remaining characters in the string.
Please note that if the string comes from an untrusted source that it
should be sanitized before use since otherwise the content of an
arbitrary readable file might be incorporated into the image
label (a security risk).

If the -label option appears multiple times, only the last label is
stored.

In PNG images, the label is stored in a \fBtEXt\fP or \fBzTXt\fP chunk
with the keyword "label".

When converting to \fIPostScript\fP, use this option to specify a header
string to print above the image. Specify the label font with
\fB-font\fP.

When creating a montage, by default the label associated with an image
is displayed with the corresponding tile in the montage.  Use the
\fB+label\fP option to suppress this behavior.


.TP
.B "-lat \fI<width>x<height>{+-}<offset>{%}"\fP
\fRperform local adaptive thresholding

Perform local adaptive thresholding using the specified width, height,
and offset.  The offset is a distance in sample space from the mean,
as an absolute integer ranging from 0 to the maximum sample value or
as a percentage.  If the percent option is supplied, then the offset
is computed as a percentage of the quantum range.  It is strongly
recommended to use the percent option so that results are not
sensitive to pixel quantum depth.

For example,

.nf
     -colorspace gray -lat "10x10-5%"
.fi

will help clarify a scanned grayscale or color document, producing a
bi-level equivalent.
.TP
.B "-level \fI<black_point>{,<gamma>}{,<white_point>}{%}"\fP
\fRadjust the level of image contrast

Give one, two or three values delimited with commas: black-point, gamma,
white-point (e.g. 10,1.0,250 or 2%,0.5,98%). The black and white
points range from 0 to MaxRGB or from 0 to 100%; if the white point is
omitted it is set to MaxRGB-black_point. If a "%" sign is present
anywhere in the string, the black and white points are percentages of
MaxRGB. Gamma is an exponent that ranges from 0.1 to 10.; if it is
omitted, the default of 1.0 (no gamma correction) is assumed. This
interface works similar to Photoshop's "Image->Adjustments->Levels..."
"Input Levels" interface.
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

By default, resource limits are estimated based on the available
resources and capabilities of the system. The resource limits are
\fBDisk\fP, maximum total disk space consumed; \fBFile\fP, maximum
number of file descriptors allowed to be open at once; \fBMap\fP,
maximum total number of file bytes which may be memory mapped;
\fBMemory\fP, maximum total number of bytes of heap memory used for
image storage; \fBPixels\fP, maximum absolute image size (per image);
\fBWidth\fP, maximum image pixels width; \fBHeight\fP, maximum image
pixels height; \fBRead\fP, maximum number of uncompressed bytes to
read; and \fBThreads\fP, the maximum number of worker threads to use
per OpenMP thread team.

The \fBDisk\fP and \fBMap\fP resource limits are used to decide if
(for a given image) the decoded image ("pixel cache") should be stored
in heap memory (RAM), in a memory-mapped disk file, or in a disk file
accessed via read/write I/O.

The number of total pixels in one image (\fBPixels\fP), and/or the
width/height (\fBWidth\fP/\fBHeight\fP), may be limited in order to
force the reading, or creation of images larger than the limit (in
pixels) to intentionally fail. The disk limit (\fBDisk\fP)
establishes an overall limit since using the disk is the means of last
resort. When the disk limit has been reached, no more images may be
read.

The amount of uncompressed data read when reading one image may be
limited by the \fBRead\fP limit.  Reading the image fails when the
limit is hit.  This option is useful if the data is read from a stream
(pipe) or from a compressed file such as a gzipped file.  Some files
are very compressable and so a small compressed file can decompress to
a huge amount of data.  This option also defends against files which
produce seemingly endless loops while decoding by seeking backwards in
the file.

The value argument is an absolute value, but may have standard binary
suffix characters applied ('K', 'M', 'G', 'T', 'P', 'E') to apply a
scaling to the value (based on a multiplier of 1024). Any additional
characters are ignored. For example, '-limit Pixels 10MP' limits
the maximum image size to 10 megapixels and '-limit memory 32MB
-limit map 64MB' limits memory and memory mapped files to 32
megabytes and 64 megabytes respectively.

Resource limits may also be set using environment variables. The
environment variables \fBMAGICK_LIMIT_DISK\fP,
\fBMAGICK_LIMIT_FILES\fP, \fBMAGICK_LIMIT_MAP\fP,
\fBMAGICK_LIMIT_MEMORY\fP, \fBMAGICK_LIMIT_PIXELS\fP,
\fBMAGICK_LIMIT_WIDTH\fP, \fBMAGICK_LIMIT_HEIGHT\fP.
\fBMAGICK_LIMIT_READ\fP, and \fBOMP_NUM_THREADS\fP may be used to
set the limits for disk space, open files, memory mapped size, heap
memory, per-image pixels, image width, image height, and threads
respectively.

Use the option -list resource list the current limits.
.TP
.B "-linewidth"
\fRthe line width for subsequent draw operations
.TP
.B "-list \fI<type>"\fP
\fRthe type of list

Choices are: \fBColor\fP, \fBDelegate\fP, \fBFormat\fP, \fBMagic\fP,
\fBModule\fP, \fBResource\fP, or \fBType\fP. The \fBModule\fP option
is only available if GraphicsMagick was built to support loadable modules.

This option lists information about the GraphicsMagick configuration.
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log

This option specifies the format for the log printed when the \fB-debug\fP
option is active.

You can display the following components by embedding
special format characters:

.nf
     %d   domain
     %e   event
     %f   function
     %l   line
     %m   module
     %p   process ID
     %r   real CPU time
     %t   wall clock time
     %u   user CPU time
     %%   percent sign
     \\n   newline
     \\r   carriage return
.fi

For example:

.nf
    gm convert -debug coders -log "%u %m:%l %e" in.gif out.png
.fi

The default behavior is to print all of the components.
.TP
.B "-loop \fI<iterations>"\fP
\fRadd Netscape loop extension to your GIF animation

A value other than zero forces the animation to repeat itself up to
\fIiterations\fP
times.
.TP
.B "-magnify"
\fRmagnify the image

The image size is doubled using linear interpolation.
.TP
.B "-magnify \fI<factor>"\fP
\fRmagnify the image

The displayed image is magnified by \fBfactor\fP.
.TP
.B "-map \fI<filename>"\fP
\fRchoose a particular set of colors from this image

[\fIconvert\fP or \fImogrify\fP]

By default, color reduction chooses an optimal set of colors that best
represent the original image. Alternatively, you can choose a particular
set of colors from an image file with this option.

Use
\fB+map\fP to reduce
all images in the image sequence that follows to a single optimal set of colors
that best represent all the images.  The sequence of images
is terminated by the appearance of any option.
If the \fB+map\fP
option appears after all of the input images, all images are mapped.
.TP
.B "-map \fI<type>"\fP
\fRdisplay image using this type.

[\fIanimate\fP or \fIdisplay\fP]

Choose from these \fIStandard Colormap\fP types:

.nf
     best
     default
     gray
     red
     green
     blue
.fi

The \fIX server\fP must support the \fIStandard Colormap\fP you choose,
otherwise an error occurs. Use \fBlist\fP as the type and \fBdisplay\fP
searches the list of colormap types in \fBtop-to-bottom\fP order until
one is located. See \fIxstdcmap(1)\fP for one way of creating Standard
Colormaps.
.TP
.B "-mask \fI<filename>"\fP
\fRSpecify a clipping mask

The image read from the file is used as a clipping mask.  It must have
the same dimensions as the image being masked.

If the mask image contains an opacity channel, the opacity of each
pixel is used to define the mask.  Otherwise, the intensity (gray
level) of each pixel is used.  Unmasked (black) pixels are modified
while masked pixels (not black) are protected from alteration.

Use \fB+mask\fP to remove the clipping mask.

It is not necessary to use \fB-clip\fP to activate the mask; \fB-clip\fP
is implied by \fB-mask\fP.
.TP
.B "-matte"
\fRstore matte channel if the image has one

If the image does not have a matte channel, create an opaque one.

Use \fB+matte\fP to ignore the matte channel (treats it as opaque) and to avoid writing a
matte channel in the output file.

For the compare command, \fB-matte\fP will add an opaque matte
channel to images if they do not already have a matte channel, and
matte will be enabled for both images.  Likewise, if \fB+matte\fP is
used, the matte channel is disabled for both images.  This makes it
easier to compare images regardless of if they already have a matte
channel.
.TP
.B "-mattecolor \fI<color>"\fP
\fRspecify the color to be used with the \fB-frame\fP option

The color is specified using the format described under the \fB-fill\fP
option.
.TP
.B "-maximum-error \fI<limit>"\fP
\fRspecifies the maximum amount of total image error

Specifies the maximum amount of total image error (based on comparison
using a specified metric) before an error ("image difference exceeds
limit") is reported.  The error is reported via a non-zero command
execution return status.
.TP
.B "-median \fI<radius>"\fP
\fRapply a median filter to the image
.TP
.B "-metric \fI<metric>"\fP
\fRcomparison metric (MAE, MSE, PAE, PSNR, RMSE)
.TP
.B "-minify \fI<factor>"\fP
\fRminify the image

The image size is halved using linear interpolation.
.TP
.B "-mode \fI<value>"\fP
\fRmode of operation

The available montage modes are \fBframe\fP to place the images in a
rectangular grid while adding a decorative frame with dropshadow,
\fBunframe\fP to place undecorated images in a rectangular grid, and
\fBconcatenate\fP to pack the images closely together without any
well-defined grid or decoration. 
.TP
.B "-modulate \fIbrightness[,saturation[,hue]]"\fP
\fRvary the brightness, saturation, and hue of an image

Specify the percent change in brightness, color saturation, and
hue separated by commas. Default argument values are 100 percent,
resulting in no change. For example, to increase the color brightness
by 20% and decrease the color saturation by 10% and leave the hue
unchanged, use: \fB-modulate 120,90\fP.

Hue is the percentage of absolute rotation from the current
position. For example 50 results in a counter-clockwise rotation of 90
degrees, 150 results in a clockwise rotation of 90 degrees, with 0 and
200 both resulting in a rotation of 180 degrees.
.TP
.B "-monitor"
\fRshow progress indication

A simple command-line progress indication is shown while the command is
running. The process indication shows the operation currently being
performed and the percent completed. Commands using X11 may replace the
command line progress indication with a graphical one once an image has
been displayed.
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-morph \fI<frames>"\fP
\fRmorphs an image sequence

Both the image pixels and size are linearly interpolated to give the appearance
of a meta-morphosis from one image to the next.

The sequence of images
is terminated by the appearance of any option.
If the \fB-morph\fP
option appears after all of the input images, all images are morphed.
.TP
.B "-mosaic"
\fRcreate a mosaic from an image or an image sequence

The \fB-mosaic\fP option provides a flexible way to composite one or
more images onto a solid-color canvas image. It works similar to
\fB-flatten\fP except that a base canvas image is automatically
created with a suitable size given the image size, page dimensions,
and page offsets of images to be composited.  The color of the base
canvas image may be set via the \fB-background\fP option.  The
default canvas color is 'white', but 'black' or 'transparent' may be
more suitable depending on the composition algorithm requested.

The \fB-compose\fP option may be used to specify the composition
algorithm to use when compositing the subsequent image on the base
canvas.

The \fB-page\fP option can be used to establish the dimensions of the
mosaic and to position the subsequent image within the mosaic.  If the
\fB-page\fP argument does not specify width and height, then the
canvas dimensions are evaluated based on the image sizes and
offsets.

The sequence of images is terminated by the appearance of any option.
If the \fB-mosaic\fP option appears after all of the input images,
all images are included in the mosaic.

The following is an example of composing an image based on red, green,
and blue layers extracted from a sequence of images and pasted on the
canvas image at specified offsets:

.nf
    gm convert -background black \\
              -compose CopyRed   -page +0-100 red.png \\
              -compose CopyGreen -page +0+40  green.png \\
              -compose CopyBlue  -page +0+180 blue.png \\
              -mosaic output.png
.fi
.TP
.B "-motion-blur \fI<radius>{x<sigma>}{+angle}"\fP
\fRSimulate motion blur

Simulate motion blur by convolving the image with a Gaussian operator of
the given radius and standard deviation (sigma). For reasonable results,
radius should be larger than sigma. If radius is zero, then a suitable
radius is automatically selected based on sigma. The angle specifies the
angle that the object is coming from (side which is blurred).
.TP
.B "-name"
\fRname an image
.TP
.B "-negate"
\fRreplace every pixel with its complementary color

The red, green, and blue intensities of an image are negated.
White becomes black,
yellow becomes blue, etc.
Use \fB+negate\fP
to only negate the grayscale pixels of the image.
.TP
.B "-noise \fI<radius|type>"\fP
\fRadd or reduce noise in an image

The principal function of noise peak elimination filter is to smooth the
objects within an image without losing edge information and without creating
undesired structures. The central idea of the algorithm is to replace a
pixel with its next neighbor in value within a pixel window, if this pixel
has been found to be noise. A pixel is defined as noise if and only if
this pixel is a maximum or minimum within the pixel window.

Use \fBradius\fP to specify the width of the neighborhood.

Use \fB+noise\fP followed by a noise type to add noise to an image.
The noise added modulates the existing image pixels. Choose from these
noise types:

.nf
     Uniform
     Gaussian
     Multiplicative
     Impulse
     Laplacian
     Poisson
     Random (uniform distribution)
.fi
.TP
.B "-noop"
\fRNOOP (no option)

The \fB-noop\fP option can be used to terminate a group of images
and reset all options to their default values, when no other option is
desired.
.TP
.B "-normalize"
\fRtransform image to span the full range of color values

This is a contrast enhancement technique based on the image histogram.

When computing the contrast enhancement values, the histogram edges
are truncated so that the majority of the image pixels are considered
in the constrast enhancement, and outliers (e.g. random noise or
minute details) are ignored.  The default is that 0.1 percent of the
histogram entries are ignored.  The percentage of the histogram to
ignore may be specified by using the \fB-set\fP option with the
\fBhistogram-threshold\fP parameter similar to \fB-set
histogram-threshold 0.01\fP to specify 0.01 percent.  Use 0 percent
to use the entire histogram, with possibly diminished contrast
enhancement.
.TP
.B "-opaque \fI<color>"\fP
\fRchange this color to the pen color within the image

The color is specified using the format described under the
\fB-fill\fP option.  The color is replaced if it is identical to the
target color, or close enough to the target color in a 3D space as
defined by the Euclidean distance specified by \fB-fuzz\fP.

See \fB-fill\fP and \fB-fuzz\fP for more details.
.TP
.B "-operator \fIchannel operator rvalue[%]"\fP
\fRapply a mathematical, bitwise, or value operator to an image channel

Apply a low-level mathematical, bitwise, or value operator to a selected
image channel or all image channels. Operations which result in negative
results are reset to zero, and operations which overflow the available
range are reset to the maximum possible value.

Select a channel from: \fBRed\fP, \fBGreen\fP, \fBBlue\fP,
\fBOpacity\fP, \fBMatte\fP, \fBCyan\fP, \fBMagenta\fP, \fBYellow\fP,
\fBBlack\fP, \fBAll\fP, or \fBGray\fP. \fBAll\fP only modifies the
color channels and does not modify the \fBOpacity\fP channel. Except for
the threshold operators, \fBAll\fP operates on each channel
independently so that operations are on a per-channel basis.

\fBGray\fP treats the color channels as a grayscale intensity and
performs the requested operation on the equivalent pixel intensity so the
result is a gray image.
Select an operator from \fBAdd\fP, \fBAnd\fP, \fBAssign\fP,
\fBDepth\fP, \fBDivide\fP, \fBGamma\fP, \fBNegate\fP,
\fBLShift\fP, \fBLog\fP, \fBMax\fP, \fBMin\fP, \fBMultiply\fP,
\fBOr\fP, \fBPow\fP, \fBRShift\fP, \fBSubtract\fP,
\fBThreshold\fP, \fBThreshold-White\fP,
\fBThreshold-White-Negate\fP, \fBThreshold-Black\fP,
\fBThreshold-Black-Negate\fP, \fBXor\fP, \fBNoise-Gaussian\fP,
\fBNoise-Impulse\fP, \fBNoise-Laplacian\fP,
\fBNoise-Multiplicative\fP, \fBNoise-Poisson\fP,
\fBNoise-Random\fP, and \fBNoise-Uniform\fP.

Rvalue may be any floating point or integer value. Normally rvalue will
be in the range of 0 to MaxRGB, where MaxRGB is the largest quantum value
supported by the GraphicsMagick build (255, 65535, or 4294967295) but
values outside this range are useful for some arithmetic operations.
Arguments to logical or bit-wise operations are rounded to a positive
integral value prior to use. If a percent (\fB%\fP) symbol is appended
to the argument, then the argument has a range of 0 to 100 percent.

The following is a description of the operators:

.in 15

.in 15
.B "Add"
.in 20
 \fR
.in 20
Result is rvalue added to channel value.

.in 15
.in 15
.B "And"
.in 20
 \fR
.in 20
Result is the logical AND of rvalue with channel value.

.in 15
.in 15
.B "Assign"
.in 20
 \fR
.in 20
Result is rvalue.

.in 15
.in 15
.B "Depth"
.in 20
 \fR
.in 20
Result is channel value adjusted so that it may be (approximately)
stored in the specified number of bits without additional loss.

.in 15
.in 15
.B "Divide"
.in 20
 \fR
.in 20
Result is channel value divided by rvalue.

.in 15
.in 15
.B "Gamma"
.in 20
 \fR
.in 20
Result is channel value gamma adjusted by rvalue.

.in 15
.in 15
.B "LShift"
.in 20
 \fR
.in 20
Result is channel value bitwise left shifted by rvalue bits.

.in 15
.in 15
.B "Log"
.in 20
 \fR
.in 20
Result is computed as log(value*rvalue+1)/log(rvalue+1).

.in 15
.in 15
.B "Max"
.in 20
 \fR
.in 20
Result is assigned to rvalue if rvalue is greater than value.

.in 15
.in 15
.B "Min"
.in 20
 \fR
.in 20
Result is assigned to rvalue if rvalue is less than value.

.in 15
.in 15
.B "Multiply"
.in 20
 \fR
.in 20
Result is channel value multiplied by rvalue.

.in 15
.in 15
.B "Negate"
.in 20
 \fR
.in 20
Result is inverse of channel value (like a film negative). An rvalue
must be supplied but is currently not used. Inverting the image twice
results in the original image.

.in 15
.in 15
.B "Or"
.in 20
 \fR
.in 20
Result is the logical OR of rvalue with channel value.

.in 15
.in 15
.B "Pow"
.in 20
 \fR
.in 20
Result is computed as pow(value,rvalue). Similar to Gamma except that
rvalue is not inverted.

.in 15
.in 15
.B "RShift"
.in 20
 \fR
.in 20
Result is channel value bitwise right shifted by rvalue bits.

.in 15
.in 15
.B "Subtract"
.in 20
 \fR
.in 20
Result is channel value minus rvalue.

.in 15
.in 15
.B "Threshold"
.in 20
 \fR
.in 20
Result is maximum (white) if channel value is greater than rvalue,
or minimum (black) if it is less than or equal to rvalue. If \fBall\fP
channels are specified, then thresholding is done based on computed pixel
intensity.

.in 15
.in 15
.B "Threshold-white"
.in 20
 \fR
.in 20
Result is maximum (white) if channel value is greater than rvalue and
is unchanged if it is less than or equal to rvalue. This can be used to
remove apparent noise from the bright parts of an image. If \fBall\fP
channels are specified, then thresholding is done based on computed pixel
intensity.

.in 15
.in 15
.B "Threshold-White-Negate"
.in 20
 \fR
.in 20
Result is set to black if channel value is greater than
rvalue and is unchanged if it is less than or equal to rvalue. If
\fBall\fP channels are specified, then thresholding is done based on
computed pixel intensity.

.in 15
.in 15
.B "Threshold-black"
.in 20
 \fR
.in 20
Result is minimum (black) if channel value is less than than rvalue
and is unchanged if it is greater than or equal to rvalue. This can be
used to remove apparent noise from the dark parts of an image. If
\fBall\fP channels are specified, then thresholding is done based on
computed pixel intensity.

.in 15
.in 15
.B "Threshold-Black-Negate"
.in 20
 \fR
.in 20
Result is set to white if channel value is less than than
rvalue and is unchanged if it is greater than or equal to rvalue. If
\fBall\fP channels are specified, then thresholding is done based on
computed pixel intensity.

.in 15
.in 15
.B "Xor"
.in 20
 \fR
.in 20
Result is the logical XOR of rvalue with channel value. An
interesting property of XOR is that performing the same operation twice
results in the original value.

.in 15
.in 15
.B "Noise-Gaussian"
.in 20
 \fR
.in 20
Result is the current channel value modulated with gaussian noise
according to the intensity specified by rvalue.

.in 15
.in 15
.B "Noise-Impulse"
.in 20
 \fR
.in 20
Result is the current channel value modulated with impulse noise
according to the intensity specified by rvalue.

.in 15
.in 15
.B "Noise-Laplacian"
.in 20
 \fR
.in 20
Result is the current channel value modulated with laplacian noise
according to the intensity specified by rvalue.

.in 15
.in 15
.B "Noise-Multiplicative"
.in 20
 \fR
.in 20
Result is the current channel value modulated with multiplicative
gaussian noise according to the intensity specified by rvalue.

.in 15
.in 15
.B "Noise-Poisson"
.in 20
 \fR
.in 20
Result is the current channel value modulated with poisson noise
according to the intensity specified by rvalue.

.in 15
.in 15
.B "Noise-Random"
.in 20
 \fR
.in 20
Result is the current channel value modulated with random (uniform
distribution) noise according to the intensity specified by rvalue.
The initial noise intensity (rvalue=1.0) is the range of one pixel
quantum span.

.in 15
.in 15
.B "Noise-Uniform"
.in 20
 \fR
.in 20
Result is the channel value with uniform noise applied according to
the intensity specified by rvalue.

.in 15



As an example, the \fBAssign\fP operator assigns a fixed value to a
channel. For example, this command sets the red channel to the mid-range
value:

.nf
    gm convert in.bmp -operator red assign "50%" out.bmp
.fi

The following applies 50% thresholding to the image and returns a gray
image:

.nf
    gm convert in.bmp -operator gray threshold "50%" out.bmp
.fi
.TP
.B "-ordered-dither \fI<channeltype> <NxN>"\fP
\fRordered dither the image

The channel or channels specified in the \fBchanneltype\fP argument are
reduced to binary, using an ordered dither method. The choices for
\fBchanneltype\fP are \fBAll\fP, \fBIntensity\fP, \fBRed\fP,
\fBGreen\fP, \fBBlue\fP, \fBCyan\fP, \fBMagenta\fP, \fBYellow\fP,
\fBBlack\fP, and \fBOpacity\fP

When \fBchanneltype\fP is "All", the color samples are dithered into
a gray level and then that gray level is stored in the three color
channels.  Separately, the opacity channel is dithered into a bilevel
opacity value which is stored in the opacity channel.

When \fBchanneltype\fP is "Intensity", only the color samples are
dithered. When \fBchanneltype\fP is "opacity" or "matte", only the
opacity channel is dithered. When a color channel is specified, only that
channel is dithered.

The choices for N are 2 through 7. The image is divided into
NxN pixel tiles.  In each tile, some or all pixels are turned to
white depending on their intensity.  For each N, (N**2)+1 levels
of gray can be represented.  For N == 2, 3, or 4, the pixels
are turned to white in an order that maximizes dispersion (i.e.,
reduces granularity), while
for N == 5, 6, and 7, they are turned to white in an order that
creates a roughly circular black blob in the middle of each tile.
An attractive "half-tone" looking image can be obtained by first
rotating the image 45 degrees, performing a 5x5 ordered-dither
operation, then rotating it back to the original orientation and
cropping to the original image dimensions.  If the original image
is gamma-encoded, it is adviseable to convert it to linear intensity
first, e.g., with the "-gamma 0.45455" option.
.TP
.B "-output-directory \fI<directory>"\fP
\fRoutput files to directory

Use -output-directory to specify a directory under which to write the
output files. Normally mogrify overwrites the input files, but with
this option the output files may be written to a different directory
tree so that the input files are preserved. The algorithm used
preserves all of the input path specification in the output path so
that the user-specified input path (including any sub-directory part)
is appended to the output path. If the input file lacks an extension,
then a suitable extension is automatically added to the output file.
The user is responsible for creating the output directory specified as
an argument, but subdirectories will be created as needed if the
\fB-create-directories\fP option is supplied.  This option may be
used to apply transformations on files from one directory and write
the transformed files to a different directory.  In conjunction with
\fB-create-directories\fP, this option is designed to support
transforming whole directory trees of files provided that the relative
path of the input file is included as part the list of filenames.
.TP
.B "-orient \fI<orientation>"\fP
\fRSet the image orientation attribute

Sets the image orientation attribute.  The image orientation attribute
is compatible with the TIFF orientation tag (and the EXIF orientation
tag).  Accepted values are \fBundefined\fP, \fBTopLeft\fP,
\fBTopRight\fP, \fBBottomRight\fP, \fBBottomLeft\fP,
\fBLeftTop\fP, \fBRightTop\fP, \fBRightBottom\fP,
\fBLeftBottom\fP, and hyphenated versions thereof
(e.g. \fBleft-bottom\fP).  Please note that GraphicsMagick does not
include an EXIF editor so if an EXIF profile is written to the output
image, the value in the EXIF profile might not match the image.  It is
possible for an image file to indicate its orientation in several
different ways simultaneously.
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas

Use this option to specify the dimensions of the
\fIPostScript\fP page
in dots per inch or a TEXT page in pixels. The choices for a PostScript
page are:

.nf
     11x17         792  1224
     Ledger       1224   792
     Legal         612  1008
     Letter        612   792
     LetterSmall   612   792
     ArchE        2592  3456
     ArchD        1728  2592
     ArchC        1296  1728
     ArchB         864  1296
     ArchA         648   864
     A0           2380  3368
     A1           1684  2380
     A2           1190  1684
     A3            842  1190
     A4            595   842
     A4Small       595   842
     A5            421   595
     A6            297   421
     A7            210   297
     A8            148   210
     A9            105   148
     A10            74   105
     B0           2836  4008
     B1           2004  2836
     B2           1418  2004
     B3           1002  1418
     B4            709  1002
     B5            501   709
     C0           2600  3677
     C1           1837  2600
     C2           1298  1837
     C3            918  1298
     C4            649   918
     C5            459   649
     C6            323   459
     Flsa          612   936
     Flse          612   936
     HalfLetter    396   612
.fi

For convenience you can specify the page size by media (e.g. A4, Ledger,
etc.). Otherwise, \fB-page\fP behaves much like
\fB-geometry\fP (e.g.  -page letter+43+43>).

This option is also used to place subimages when writing to a multi-image
format that supports offsets, such as GIF89 and MNG.  When used for this
purpose the offsets are always  measured from the
top left corner of the canvas and are not affected by the \fB-gravity\fP
option.
To position a GIF or MNG image, use \fB-page\fP\fI{+-}<x>{+-}<y>\fP
(e.g. -page +100+200).  When writing to a MNG file, a \fB-page\fP
option appearing ahead of the first image in the sequence with nonzero
width and height defines the width and height values that are written in
the \fBMHDR\fP chunk.  Otherwise, the MNG width and height are computed
from the bounding box that contains all images in the sequence.  When
writing a GIF89 file, only the bounding box method is used to determine its
dimensions.

For a PostScript page, the image is sized as in \fB-geometry\fP and positioned
relative to the lower left hand corner of the page by
{+-}<\fBx\fP\fIoffset\fP>{+-}<\fBy\fP
\fIoffset>\fP. Use
-page 612x792>, for example, to center the
image within the page. If the image size exceeds the PostScript page, it
is reduced to fit the page.
The default gravity for the \fB-page\fP
option is \fINorthWest\fP, i.e., positive \fBx\fP and
\fBy\fP \fIoffset\fP are measured rightward and downward from the top
left corner of the page, unless the \fB-gravity\fP option is present with
a value other than \fINorthWest\fP.

The default page dimensions for a TEXT image is 612x792.

This option is used in concert with \fB-density\fP.

Use \fB+page\fP to remove the page settings for an image.
.TP
.B "-paint \fI<radius>"\fP
\fRsimulate an oil painting

Each pixel is replaced by the most frequent color in a circular neighborhood
whose width is specified with \fIradius\fP.
.TP
.B "-pause \fI<seconds>"\fP
\fRpause between animation loops [animate]

Pause for the specified number of seconds before repeating the
animation.
.TP
.B "-pause \fI<seconds>"\fP
\fRpause between snapshots [import]

Pause for the specified number of seconds before taking the next
snapshot.
.TP
.B "-pen \fI<color>"\fP
\fR(This option has been replaced by the -fill option)
.TP
.B "-ping"
\fRefficiently determine image characteristics

Use this option to disable reading the image pixels so that image
characteristics such as the image dimensions may be obtained very
quickly. For identify, use +ping to force reading the image pixels so
that the pixel read rate may be included in the displayed information.
.TP
.B "-pointsize \fI<value>"\fP
\fRpointsize of the PostScript, X11, or TrueType font
.TP
.B "-preview \fI<type>"\fP
\fRimage preview type

Use this option to affect the preview operation of an image (e.g.
convert file.png -preview Gamma Preview:gamma.png). Choose
from these previews:

.nf
     Rotate
     Shear
     Roll
     Hue
     Saturation
     Brightness
     Gamma
     Spiff
     Dull
     Grayscale
     Quantize
     Despeckle
     ReduceNoise
     AddNoise
     Sharpen
     Blur
     Threshold
     EdgeDetect
     Spread
     Shade
     Raise
     Segment
     Solarize
     Swirl
     Implode
     Wave
     OilPaint
     CharcoalDrawing
     JPEG
.fi

The default preview is \fBJPEG\fP.
.TP
.B "-process \fI<command>"\fP
\fRprocess a sequence of images using a process module

The command argument has the form \fBmodule=arg1,arg2,arg3,...,argN\fP
where \fBmodule\fP is the name of the module to invoke (e.g. "Analyze")
and arg1,arg2,arg3,...,argN are an arbitrary number of arguments to
pass to the process module.
The sequence of images
is terminated by the appearance of any option.

If the \fB-process\fP
option appears after all of the input images, all images are processed.

For example:

.nf
     gm convert logo: -process Analyze= \\
       -format "%[BrightnessMean],%[BrightnessStddev]" info:-
     51952,23294

.nf
.TP
.B "-profile \fI<filename>"\fP
\fRadd ICM, IPTC, or generic profile  to image

-profile filename adds an ICM (ICC color management), IPTC
(newswire information), or a generic (including Exif) profile to the image
.

Use +profile icm, +profile iptc, or
+profile profile_name to remove the respective profile.
Multiple profiles may be listed, separated by commas. Profiles may be
excluded from subsequent listed matches by preceding their name with
an exclamation point.  For example, +profile '!icm,*' strips
all profiles except for the ICM profile.  Use identify
-verbose to find out what profiles are in the image file.  Use
+profile "*" to remove all profiles.
Writing the image to a format that does not support profiles will
of course also cause all profiles to be removed.  The JPEG and PNG
formats will store any profiles that have been read and not removed.
In JPEG they are stored in APP1 markers, and in PNG they are stored
as hex-coded binary in compressed zTXt chunks, except for the iCC
chunk which is stored in the iCCP chunk.

To extract a profile, the \fB-profile\fP option is not used.  Instead,
simply write the file to an image
format such as \fIAPP1, 8BIM, ICM,\fP or \fIIPTC\fP.

For example, to extract the Exif data (which is stored in JPEG files
in the \fIAPP1\fP profile), use


.nf
    gm convert cockatoo.jpg exifdata.app1
.fi
Note that GraphicsMagick does not attempt to update any profile to
reflect changes made to the image, e.g., rotation from portrait to landscape
orientation, so it is possible that the preserved profile may contain
invalid data.
.TP
.B "-preserve-timestamp"
\fRpreserve the original timestamps of the file

Use this option to preserve the original modification and access
timestamps of the file, even if it has been modified.
.TP
.B "+progress"
\fRdisable progress monitor and busy cursor

By default, when an image is displayed, a progress monitor bar is shown
in the top left corner of an existing image display window, and the
current cursor is replaced with an hourglass cursor. Use \fB+progress\fP
to disable the progress monitor and busy cursor during display operations.
While the progress monitor is disabled for all operations, the busy
cursor continues to be enabled for non-display operations such as image
processing. This option is useful for non-interactive display operations,
or when a "clean" look is desired.
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
 For the JPEG and MPEG image formats, quality is 0 (lowest image
quality and highest compression) to 100 (best quality but least
effective compression). The default quality is 75.  Use the
\fB-sampling-factor\fP option to specify the factors for chroma
downsampling.  To use the same quality value as that found by the JPEG
decoder, use the -define jpeg:preserve-settings flag.

For the MIFF image format, and the TIFF format while using ZIP
compression, quality/10 is the zlib compression level, which is 0 (worst
but fastest compression) to 9 (best but slowest). It has no effect on the
image appearance, since the compression is always lossless.

For the JPEG-2000 image format, quality is mapped using a non-linear
equation to the compression ratio required by the Jasper library. This
non-linear equation is intended to loosely approximate the quality
provided by the JPEG v1 format. The default quality value 75 results in
a request for 16:1 compression. The quality value 100 results in
a request for non-lossy compression.

For the MNG and PNG image formats, the quality value sets the zlib compression
level (quality / 10) and filter-type (quality % 10). Compression levels
range from 0 (fastest compression) to 100 (best but slowest). For compression
level 0, the Huffman-only strategy is used, which is fastest but not
necessarily the worst compression.

If
filter-type is 4 or less, the specified filter-type is used for all scanlines:

.nf
     0: none
     1: sub
     2: up
     3: average
     4: Paeth
.fi

If filter-type is 5, adaptive filtering is used when quality is greater
than 50 and the image does not have a color map, otherwise no filtering
is used.

If filter-type is 6, adaptive filtering
with \fIminimum-sum-of-absolute-values\fP
is used.

Only if the output is MNG, if filter-type is 7, the LOCO color transformation
and adaptive filtering with \fIminimum-sum-of-absolute-values\fP
are used.

The default is quality is 75, which means nearly the best compression with
adaptive filtering.  The quality setting has no effect on the appearance
of PNG and MNG images, since the compression is always lossless.

For further information, see the PNG
specification.

When writing a JNG image with transparency, two quality values are required,
one for the main image and one for the grayscale image that conveys the
opacity channel.  These are written as a single integer equal to the main
image quality plus 1000 times the opacity quality.  For example, if you
want to use quality 75 for the main image and quality 90 to compress
the opacity data, use -quality 90075.

For the PNM family of formats (PNM, PGM, and PPM) specify a quality
factor of zero in order to obtain the ASCII variant of the format. Note
that -compress \fInone\fP used to be used to trigger ASCII output but
provided the opposite result of what was expected as compared with other
formats.

For the TIFF format, the JPEG, WebP, Zip, and Zstd compression
algorithms are influenced by the quality value.  JPEG and WebP provide
lossy compression so higher quality produces a larger file with less
degradation.  The Zip and Zstd compression algorithms (and WebP in
lossless mode) are lossless and for these algorithms a higher
\'quality' means to work harder to produce a smaller file, but with no
difference in image quality.
.TP
.B "-raise \fI<width>x<height>"\fP
\fRlighten or darken image edges

This will create a 3-D effect. See \fB-geometry\fP for details
details about the geometry specification. Offsets are not used.

Use \fB-raise\fP to create a raised effect, otherwise use \fB+raise\fP.
.TP
.B "-random-threshold \fI<channeltype> <LOWxHIGH>"\fP
\fRrandom threshold the image

The channel or channels specified in the <channeltype> argument are
reduced to binary, using an random-threshold method. The choices for
\fBchanneltype\fP are \fBAll\fP, \fBIntensity\fP, \fBRed\fP,
\fBGreen\fP, \fBBlue\fP, \fBCyan\fP, \fBMagenta\fP, \fBYellow\fP,
\fBBlack\fP, and \fBOpacity\fP

When \fBchanneltype\fP is "All", the color samples are thresholded into
a graylevel and then that gray level is stored in the three color
channels. Separately, the opacity channel is thresholded into a bilevel
opacity value which is stored in the opacity channel. For each pixel, a
new random number is used to establish the threshold to be used. The
threshold never exceeds the specified maximum (HIGH) and is never less
than the specified minimum (LOW).

When \fBchanneltype\fP is "intensity", only the color samples are
thresholded. When \fBchanneltype\fP is "opacity" or "matte", only the
opacity channel is thresholded. The other named channels only threshold
the associated channel.
.TP
.B "-recolor \fI<matrix>"\fP
\fRapply a color translation matrix to image channels

A user supplied color translation matrix (expressed as a text string)
is used to translate/blend the image channels based on weightings in a
supplied matrix which may be of order 3 (color channels only), 4
(color channels plus opacity), or 5 (color channels plus opacity and
offset).  Values in the columns of the matrix (red, green, blue,
opacity) are used as multipliers with the existing channel values and
added together according to the rows of the matrix.  Matrix values are
floating point and may be negative.  The offset column (column 5) is
purely additive and is scaled such that 0.0 to 1.0 represents the
maximum quantum range (but values are not limited to this range). The
math for the color translation matrix is similar to that used by Adobe
Flash except that the offset is scaled to 1.0 (divide Flash offset by
255 for use with GraphicsMagick) so that the results are independent
of quantum depth.

An \fBidentity\fP matrix exists for each matrix order which
results in no change to the image.  The translation matrix should be
based on an alteration of the identity matrix.

Identity matrix of order 3

.nf
  1 0 0
  0 1 0
  0 0 1
.fi

which may be formatted into a convenient matrix argument similar to
(comma is treated as white space):

.nf
  -recolor "1 0 0, 0 1 0, 0 0 1"
.fi

Identity matrix of order 4

.nf
  1 0 0 0
  0 1 0 0
  0 0 1 0
  0 0 0 1
.fi

Identity matrix of order 5.  The last row is required to exist
for the purpose of parsing, but is otherwise not used.

.nf
  1 0 0 0 0
  0 1 0 0 0
  0 0 1 0 0
  0 0 0 1 0
  0 0 0 0 1
.fi

As an example, an image wrongly in BGR channel order may be converted
to RGB using this matrix (blue->red, red->blue):

.nf
  0 0 1
  0 1 0
  1 0 0
.fi

and an RGB image using standard Rec.709 primaries may be converted
to grayscale using this matrix of standard weighting factors:

.nf
  0.2126 0.7152 0.0722
  0.2126 0.7152 0.0722
  0.2126 0.7152 0.0722
.fi

and contrast may be reduced by scaling down by 80% and adding a 10%
offset:

.nf
  0.8 0.0 0.0 0.0 0.1
  0.0 0.8 0.0 0.0 0.1
  0.0 0.0 0.8 0.0 0.1
  0.0 0.0 0.0 0.8 0.1
  0.0 0.0 0.0 0.0 1.0
.fi
.TP
.B "-red-primary \fI<x>,<y>"\fP
\fRred chromaticity primary point
.TP
.B "-region \fI<width>x<height>{+-}<x>{+-}<y>"\fP
\fRapply options to a portion of the image

The \fIx\fP and \fIy\fP offsets are treated in the same manner as in \fB-crop\fP.
.TP
.B "-remote"
\fRperform a X11 remote operation

The \fB-remote\fP command sends a command to a "gm display" or "gm
animate" which is already running. The only command recognized at this
time is the name of an image file to load. This capability is very
useful to load new images without needing to restart GraphicsMagick
(e.g. for a slide-show or to use GraphicsMagick as the display engine
for a different GUI). Also see the \fB+progress\fP option for a way
to disable progress indication for a clean look while loading new images.
.TP
.B "-render"
\fRrender vector operations

Use \fB+render\fP to turn off rendering vector operations. This is
useful when saving the result to vector formats such as MVG or SVG.
.TP
.B "-repage \fI <width>x<height>+xoff+yoff[!]"\fP
\fRAdjust image page offsets

Adjust the current image page canvas and position based on a relative
page specification.  This option may be used to change the location of
a subframe (e.g. part of an animation) prior to composition.  If the
geometry specification is absolute (includes a '!'), then the offset
adjustment is absolute and there is no adjustment to page width and
height, otherwise the page width and height values are also adjusted
based on the current image dimensions.  Use \fB+repage\fP to set the
image page offsets to default.
.TP
.B "-resample \fI<horizontal>x<vertical>"\fP
\fRResample image to specified horizontal and vertical resolution

Resize the image so that its rendered size remains the same as the
original at the specified target resolution. Either the current image
resolution units or the previously set with \fB-units\fP are used to
interpret the argument. For example, if a 300 DPI image renders at 3
inches by 2 inches on a 300 DPI device, when the image has been
resampled to 72 DPI, it will render at 3 inches by 2 inches on a 72
DPI device.  Note that only a small number of image formats
(e.g. JPEG, PNG, and TIFF) are capable of storing the image
resolution. For formats which do not support an image resolution, the
original resolution of the image must be specified via \fB-density\fP
on the command line prior to specifying the resample resolution.

Note that Photoshop stores and obtains image resolution from a
proprietary embedded profile. If this profile exists in the image,
then Photoshop will continue to treat the image using its former
resolution, ignoring the image resolution specified in the standard
file header.

Some image formats (e.g. PNG) require use of metric or english units
so even if the original image used a particular unit system, if it is
saved to a different format prior to resampling, then it may be
necessary to specify the desired resolution units using \fB-units\fP
since the original units may have been lost. In other words, do not
assume that the resolution units are restored if the image has been
saved to a file.
.TP
.B "-resize \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image

This is an alias for the \fB-geometry\fP option and it behaves in the
same manner. If the \fB-filter\fP option precedes the \fB-resize\fP
option, the specified filter is used.

There are some exceptions:

When used as a \fIcomposite\fP option, \fB-resize\fP conveys the
preferred size of the output image, while \fB-geometry\fP conveys the
size and placement of the \fIcomposite image\fP within the main
image.

When used as a \fImontage\fP option, \fB-resize\fP conveys the preferred
size of the montage, while \fB-geometry\fP conveys
information about the tiles.
.TP
.B "-roll \fI{+-}<x>{+-}<y>"\fP
\fRroll an image vertically or horizontally

See \fB-geometry\fP for details the geometry specification.  The
\fIx\fP and \fIy\fP offsets are not affected by the \fB-gravity\fP
option.

A negative \fIx\fP offset rolls the image left-to-right. A negative
\fIy\fP offset rolls the image top-to-bottom.
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image

Positive angles rotate the image in a clockwise direction while
negative angles rotate counter-clockwise.

Use > to rotate the image only if its width exceeds the
height.  < rotates the image \fIonly\fP if its width is less
than the height. For example, if you specify -rotate "-90>"
and the image size is 480x640, the image is not rotated.  However, if
the image is 640x480, it is rotated by -90 degrees.  If you use
> or <, enclose it in quotation marks to prevent it
from being misinterpreted as a file redirection.

Empty triangles left over from rotating the image are filled with the
color defined as \fBbackground\fP (class \fBbackgroundColor\fP).
The color is specified using the format described under the
\fB-fill\fP option.
.TP
.B "-sample \fI<geometry>"\fP
\fRscale image using pixel sampling

See \fB-geometry\fP for details about
the geometry specification.
\fB-sample\fP ignores the \fB-filter\fP selection if the \fB-filter\fP option
is present.  Offsets, if present in the geometry string, are ignored, and
the \fB-gravity\fP option has no effect.
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors

This option specifies the sampling factors to be used by the DPX, JPEG,
MPEG, or YUV encoders for chroma downsampling. The sampling factor must
be specified while reading the raw YUV format since it is not preserved
in the file header.
Industry-standard video subsampling notation such as "4:2:2" may also
be used to specify the sampling factors. "4:2:2" is equivalent to a
specification of "2x1"

The JPEG decoder obtains the original sampling factors (and quality
settings) when a JPEG file is read. To re-use the original sampling
factors (and quality setting) when JPEG is output, use the -define
jpeg:preserve-settings flag.
.TP
.B "-scale \fI<geometry>"\fP
\fRscale the image.

See \fB-geometry\fP for details about
the geometry specification.  \fB-scale\fP uses a simpler, faster algorithm,
and it ignores the \fB-filter\fP selection if the \fB-filter\fP option
is present.  Offsets, if present in the geometry string, are ignored, and
the \fB-gravity\fP option has no effect.
.TP
.B "-scene \fI<value>"\fP
\fRset scene number

This option sets the scene number of an image or the first image in
an image sequence.
.TP
.B "-scenes \fI<value-value>"\fP
\fRrange of image scene numbers to read

Each image in the range is read
with the filename followed by a period (\fB.\fP) and the decimal scene
number.  You
can change this behavior by embedding a \fB%d, %0Nd, %o, %0No, %x, or %0Nx
printf\fP format specification in the file name. For example,

.nf
    gm montage -scenes 5-7 image.miff montage.miff
.fi

makes a montage of files image.miff.5, image.miff.6, and image.miff.7, and

.nf
    gm animate -scenes 0-12 image%02d.miff
.fi

animates files image00.miff, image01.miff, through image12.miff.
.TP
.B "-screen"
\fRspecify the screen to capture

This option indicates that the GetImage request used to obtain the image
should be done on the root window, rather than directly on the specified
window.  In this way, you can obtain pieces of other windows that overlap
the specified window, and more importantly, you can capture menus or other
popups that are independent windows but appear over the specified window.
.TP
.B "-set \fI<attribute> <value>"\fP
\fRset an image attribute

Set a named image attribute.  The attribute is set on the current
(previously specified on command line) image.
.TP
.B "+set \fI<attribute>"\fP
\fRunset an image attribute

Unset a named image attribute.  The attribute is removed from the current
(previously specified on command line) image.
.TP
.B "-segment \fI<cluster threshold>x<smoothing threshold>"\fP
\fRsegment an image

Segment an image by analyzing the histograms of the color components and
identifying units that are homogeneous with the fuzzy c-means technique.

Segmentation is a very useful fast and and approximate color quantization
algorithm for scanned printed pages or scanned cartoons. It may also be
used as a special effect. Specify \fIcluster threshold\fP as the minimum
percentage of total pixels in a cluster before it is considered valid.
For huge images containing small detail, this may need to be a tiny
fraction of a percent (e.g. 0.015) so that important detail is not lost.
\fISmoothing threshold\fP eliminates noise in the second derivative of
the histogram. As the value is increased, you can expect a smoother
second derivative. The default is 1.5. Add the \fI-verbose\fP option to
see a dump of cluster statistics given the parameters used. The
statistics may be used as a guide to help fine tune the options.
.TP
.B "-shade \fI<azimuth>x<elevation>"\fP
\fRshade the image using a distant light source

Specify \fIazimuth\fP and \fIelevation\fP as the position of the light
source. Use \fB+shade\fP to return the shading results as a grayscale
image.
.TP
.B "-shadow \fI<radius>{x<sigma>}"\fP
\fRshadow the montage
.TP
.B "-shared-memory"
\fRuse shared memory

This option specifies whether the utility should attempt to use shared
memory for pixmaps.  GraphicsMagick must be compiled with shared
memory support, and the display must support the \fIMIT-SHM\fP
extension.  Otherwise, this option is ignored.  The default is
\fBTrue\fP.
.TP
.B "-sharpen \fI<radius>{x<sigma>}"\fP
\fRsharpen the image

Use a Gaussian operator of the given radius and standard deviation
(sigma).
.TP
.B "-shave \fI<width>x<height>{%}"\fP
\fRshave pixels from the image edges

Specify the width of the region to be removed from both
sides of the image and the height of the regions to be removed from
top and bottom.
.TP
.B "-shear \fI<x degrees>x<y degrees>"\fP
\fRshear the image along the X or Y axis

Use the specified positive or negative shear angle.

Shearing slides one edge of an image along the X or Y axis, creating a
parallelogram. An X direction shear slides an edge along the X axis,
while a Y direction shear slides an edge along the Y axis. The amount
of the shear is controlled by a shear angle. For X direction shears,
\fIx degrees\fP is measured relative to the Y axis, and similarly,
for Y direction shears \fIy degrees\fP is measured relative to the X
axis.

Empty triangles left over from shearing the image are filled with the
color defined as \fBbackground\fP (class \fBbackgroundColor\fP).
The color is specified using the format described under the
\fB-fill\fP option.
.TP
.B "-silent"
\fRoperate silently
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image

Use this option to specify the width and height of raw images whose
dimensions are unknown such as \fBGRAY\fP, \fBRGB\fP, or
\fBCMYK\fP. In addition to width and height, use \fB-size\fP with an
offset to skip any header information in the image or tell the number
of colors in a \fBMAP\fP image file, (e.g. -size 640x512+256).

For Photo CD images, choose from these sizes:

.nf
     192x128
     384x256
     768x512
     1536x1024
     3072x2048
.fi

Finally, use this option to choose a particular resolution layer of a JBIG
or JPEG image (e.g. -size 1024x768).
.TP
.B "-snaps \fI<value>"\fP
\fRnumber of screen snapshots

Use this option
to grab more than one image from the X server screen, to create
an animation sequence.
.TP
.B "-solarize \fI<factor>"\fP
\fRnegate all pixels above the threshold level

Specify \fIfactor\fP as the
percent threshold of the intensity (0 - 99.9%).

This option produces a \fIsolarization\fP effect seen when exposing a
photographic film to light during the development process.
.TP
.B "-spread \fI<amount>"\fP
\fRdisplace image pixels by a random amount

\fIAmount\fP defines the size of the neighborhood around each pixel to
choose a candidate pixel to swap.
.TP
.B "-stegano \fI<offset>"\fP
\fRhide watermark within an image

Use an offset to start the image hiding some number of pixels from the
beginning of the image.  Note this offset and the image size.  You will
need this information to recover the steganographic image
(e.g. display -size 320x256+35 stegano:image.png).
.TP
.B "-stereo"
\fRcomposite two images to create a stereo anaglyph

The left side of the stereo pair is saved as the red channel of the output
image.  The right side is saved as the green channel.  Red-green stereo
glasses are required to properly view the stereo image.
.TP
.B "-strip"
\fRremove all profiles and text attributes from the image

All embedded profiles and text attributes are stripped from the image.
This is useful for images used for the web, or when output files need
to be as small as possible

Be careful not to use this option to remove author, copyright, and
license information that you are required to retain when redistributing
an image.
.TP
.B "-stroke \fI<color>"\fP
\fRcolor to use when stroking a graphic primitive

The color is specified using the format described under the \fB-fill\fP
option.

See \fB-draw\fP for further details.
.TP
.B "-strokewidth \fI<value>"\fP
\fRset the stroke width

See \fB-draw\fP for further details.
.TP
.B "-swirl \fI<degrees>"\fP
\fRswirl image pixels about the center

\fIDegrees\fP defines the tightness of the swirl.
.TP
.B "-text-font \fI<name>"\fP
\fRfont for writing fixed-width text

Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text.  The default is 14 point \fICourier\fP.

You can tag a font to specify whether it is a PostScript, TrueType, or
X11 font.  For example, Courier.ttf is a TrueType font
and x:fixed is X11.
.TP
.B "-texture \fI<filename>"\fP
\fRname of texture to tile onto the image background
.TP
.B "-threshold \fI<value>{%}"\fP
\fRthreshold the image

Modify the image such that any pixel sample with an intensity value
greater than the threshold is assigned the maximum intensity (white), or
otherwise is assigned the minimum intensity (black). If a percent prefix
is applied, then the threshold is a percentage of the available range.

To efficiently create a black and white image from a color image, use

.nf
    gm convert -threshold 50% in.png out.png
.fi

The optimum threshold value depends on the nature of the image.
In order to threshold individual channels, use the \fB-operator\fP
subcommand with it's \fBThreshold\fP, \fBThreshold-White\fP, or
\fBThreshold-Black\fP options.
.TP
.B "-thumbnail \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image (quickly)

The \fB-thumbnail\fP command resizes the image as quickly as
possible, with more concern for speed than resulting image quality.
Regardless, resulting image quality should be acceptable for many
uses.  It is primarily intended to be used to generate smaller
versions of the image, but may also be used to enlarge the image.  The
\fB-thumbnail\fP \fBgeometry\fP argument observes the same syntax
and rules as it does for \fB-resize\fP.
.TP
.B "-tile \fI<filename>"\fP
\fRtile image when filling a graphic primitive
.TP
.B "-tile \fI<geometry>"\fP
\fRlayout of images [\fImontage\fP]
.TP
.B "-title \fI<string>"\fP
\fRassign title to displayed image [\fIanimate, display, montage\fP]

Use this option to assign a specific title to the image. This is
assigned to the image window and is typically displayed in the window
title bar.  Optionally you can include the image filename, type,
width, height, Exif data, or other image attribute by embedding
special format characters described under the \fB-format\fP
option.

For example,

.nf
     -title "%m:%f %wx%h"
.fi

produces an image title of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.
.TP
.B "-transform"
\fRtransform the image

This option applies the transformation matrix from a previous
\fB-affine\fP option.

.nf
    gm convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
.fi
.TP
.B "-transparent \fI<color>"\fP
\fRmake this color transparent within the image

The color is specified using the format described under the \fB-fill\fP
option.
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm

Normally, this integer value is zero or one. A value of zero or one
causes the use of an optimal tree depth for the color reduction
algorithm

An optimal depth generally allows the best representation of the source
image with the fastest computational speed and the least amount of memory.
However, the default depth is inappropriate for some images. To assure
the best representation, try values between 2 and 8 for this parameter.
Refer to
quantize for more details.

The \fB-colors\fP or \fB-monochrome\fP option, or writing to an image
format which requires color reduction, is required for this option to
take effect.
.TP
.B "-trim"
\fRtrim an image

This option removes any edges that are exactly the same color as the
corner pixels.  Use \fB-fuzz\fP to make \fB-trim\fP remove edges that
are nearly the same color as the corner pixels.
.TP
.B "-type \fI<type>"\fP
\fRthe image type

Choose from:
\fBBilevel\fP, \fBGrayscale\fP, \fBPalette\fP,
\fBPaletteMatte\fP, \fBTrueColor\fP, \fBTrueColorMatte\fP,
\fBColorSeparation\fP, \fBColorSeparationMatte\fP, or \fBOptimize\fP.

Normally, when a format supports different subformats such as bilevel,
grayscale, palette, truecolor, and truecolor+alpha, the encoder will try
to choose a suitable subformat based on the nature of the image. The
\fB-type\fP option may be used to tailor the output subformat. By
default the output subformat is based on readily available image
information and is usually similar to the input format.

Specify -type Optimize in order to enable inspecting all pixels
(if necessary) in order to find the most efficient subformat. Inspecting
all of the pixels may be slow for very large images, particularly if they
are stored in a disk cache. If an RGB image contains only gray pixels,
then every pixel in the image must be inspected in order to decide that
the image is actually grayscale!

Sometimes a specific subformat is desired. For example, to force a JPEG
image to be written in TrueColor RGB format even though only gray pixels
are present, use

.nf
    gm convert bird.pgm -type TrueColor bird.jpg
.fi

Similarly, using -type TrueColorMatte will force the encoder to
write an alpha channel even though the image is opaque, if the output
format supports transparency.

Some pseudo-formats (e.g. the XC format) will respect the requested
type if it occurs previously on the command line.  For example, to obtain
a DirectClass solid color canvas image rather than PsuedoClass, use

.nf
    gm convert -size 640x480 -type TrueColor xc:red red.miff
.fi

Likewise, specify \fB-type\fP \fBBilevel\fP, \fBGrayscale\fP,
\fBTrueColor\fP, or \fBTrueColorMatte\fP prior to reading a Postscript
(or PDF file) in order to influence the type of image that Ghostcript
returns. Reading performance will be dramatically improved for
black/white Postscript if \fBBilevel\fP is specified, and will be
considerably faster if \fBGrayscale\fP is specified.
.TP
.B "-update \fI<seconds>"\fP
\fR
detect when image file is modified and redisplay.

Suppose that while you are displaying an image the file that is currently
displayed is over-written.
\fBdisplay\fP will automatically detect that
the input file has been changed and update the displayed image accordingly.
.TP
.B "-units \fI<type>"\fP
\fRthe units of image resolution

Choose from: \fBUndefined\fP, \fBPixelsPerInch\fP, or
\fBPixelsPerCentimeter\fP. This option is normally used in conjunction
with the \fB-density\fP option.
.TP
.B "-unsharp \fI<radius>{x<sigma>}{+<amount>}{+<threshold>}"\fP
\fRsharpen the image with an unsharp mask operator

The \fB-unsharp\fP option sharpens an image. The image is convolved
with a Gaussian operator of the given radius and standard deviation
(sigma). For reasonable results, radius should be larger than sigma. Use
a radius of 0 to have the method select a suitable radius.

The parameters are:

.in 15

.in 15
.B "radius"
.in 20
 \fR
.in 20

The radius of the Gaussian, in pixels, not counting the center pixel (default 0).

.in 15
.in 15
.B "sigma"
.in 20
 \fR
.in 20

The standard deviation of the Gaussian, in pixels (default 1.0).

.in 15
.in 15
.B "amount"
.in 20
 \fR
.in 20

The percentage of the difference between the original and the blur image that
is added back into the original (default 1.0).

.in 15
.in 15
.B "threshold"
.in 20
 \fR
.in 20

The threshold, as a fraction of MaxRGB, needed to apply the difference
amount (default 0.05).

.in 15


.TP
.B "-use-pixmap"
\fRuse the pixmap
.TP
.B "-verbose"
\fRprint detailed information about the image

This information is printed: image scene number; image name; image size;
the image class (\fIDirectClass\fP or \fIPseudoClass\fP); the total
number of unique colors; and the number of seconds to read and transform
the image. If the image is \fIDirectClass\fP, the total number of unique
colors is not displayed unless \fB-verbose\fP is specified twice since
it may take quite a long time to compute, particularly for deep images.
If the image is \fIPseudoClass\fP then its pixels are defined by indexes
into a colormap. If the image is \fIDirectClass\fP then each pixel
includes a complete and independent color specification.

If \fB-colors\fP is also specified, the total unique colors in the image
and color reduction error values are printed. Refer to quantize
for a description of these values.
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-view \fI<string>"\fP
\fRFlashPix viewing parameters
.TP
.B "-virtual-pixel \fI<method>"\fP
\fRspecify contents of "virtual pixels"

This option 
defines "virtual pixels" for use in operations that can access pixels outside
the boundaries of an image.

Choose from these methods:

.in 15

.in 15
.B "Constant"
.in 20
 \fR
.in 20

Use the image background color.

.in 15
.in 15
.B "Edge"
.in 20
 \fR
.in 20

Extend the edge pixel toward infinity (default).

.in 15
.in 15
.B "Mirror"
.in 20
 \fR
.in 20

Mirror the image.

.in 15
.in 15
.B "Tile"
.in 20
 \fR
.in 20

Tile the image.

.in 15



This option affects operations that use
virtual pixels such as \fB-blur\fP, \fB-sharpen\fP, \fB-wave\fP, etc.
.TP
.B "-visual \fI<type>"\fP
\fRanimate images using this X visual type

Choose from these visual classes:

.nf
     StaticGray
     GrayScale
     StaticColor
     PseudoColor
     TrueColor
     DirectColor
     default
     visual id
.fi

The X server must support the visual you choose, otherwise an error occurs.
If a visual is not specified, the visual class that can display the most
simultaneous colors on the default screen is chosen.
.TP
.B "-watermark \fI<brightness>x<saturation>"\fP
\fRpercent brightness and saturation of a watermark
.TP
.B "-wave \fI<amplitude>x<wavelength>"\fP
\fRalter an image along a sine wave

Specify \fIamplitude\fP and \fIwavelength\fP
of the wave.
.TP
.B "-white-point \fI<x>,<y>"\fP
\fRchromaticity white point
.TP
.B "-white-threshold \fIred[,green][,blue][,opacity]"\fP
\fRpixels above the threshold become white

Use \fB-white-threshold\fP to set pixels with values above the specified
threshold to maximum value (white). If only one value is supplied, or the
red, green, and blue values are identical, then intensity thresholding is
used. If the color threshold values are not identical then channel-based
thresholding is used, and color distortion will occur. Specify a negative
value (e.g. -1) if you want a channel to be ignored but you do want to
threshold a channel later in the list. If a percent (%) symbol is
appended, then the values are treated as a percentage of maximum
range.
.TP
.B "-window \fI<id>"\fP
\fRmake image the background of a window

\fIid\fP can be a window id or name.  Specify \fBroot\fP to
select X's root window as the target window.

By default the image is tiled onto the background of the target
window.   If \fBbackdrop\fP or \fB-geometry\fP are
specified, the image is surrounded by the background color.  Refer to
\fBX RESOURCES\fP for details.

The image will not display on the root window if the image has more
unique colors than the target window colormap allows.  Use
\fB-colors\fP to reduce the number of colors.
.TP
.B "-window-group"
\fRspecify the window group
.TP
.B "-write \fI<filename>"\fP
\fRwrite an intermediate image [\fIconvert, composite\fP]

The current image is written to the specified filename and then
processing continues using that image. The following is an example of how
several sizes of an image may be generated in one command (repeat as
often as needed):

.nf
    gm convert input.jpg -resize 50% -write input50.jpg \\
              -resize 25% input25.jpg
.fi
.TP
.B "-write \fI<filename>"\fP
\fRwrite the image to a file [\fIdisplay\fP]

If \fIfilename\fP already exists, you will be prompted as to whether it should
be overwritten.

By default, the image is written in the format that it was read in as.
To specify a particular image format, prefix \fIfilename\fP with the
image type and a colon (e.g., ps:image) or specify the image type as
the filename suffix (e.g., image.ps). Specify file as - for standard
output. If file has the extension \fB.Z\fP or \fB.gz\fP, the file
size is \fBcompressed\fP using compress or \fBgzip\fP
respectively. Precede the image file name with | to pipe to a system
command.

Use \fB-compress\fP to specify the type of image compression.

The equivalent X resource for this option is
\fBwriteFilename\fP (class \fBWriteFilename\fP).
See
"X Resources", below,
for details.
.SH ENVIRONMENT
.TP
.B "COLUMNS"
\fROutput screen width. Used when formatting text for the screen. Many
Unix systems keep this shell variable up to date, but it may need to be
explicitly exported in order for GraphicsMagick to see it.
.TP
.B "DISPLAY"
\fRX11 display ID (host, display number, and screen in the form
hostname:display.screen).
.TP
.B "HOME"
\fRLocation of user's home directory. For security reasons, now only
observed by "uninstalled" builds of GraphicsMagick which do not have
their location hard-coded or set by an installer.  When supported,
GraphicsMagick searches for configuration files in $HOME/.magick if
the directory exists. See \fBMAGICK_CODER_MODULE_PATH\fP,
\fBMAGICK_CONFIGURE_PATH\fP, and \fBMAGICK_FILTER_MODULE_PATH\fP if
more flexibility is needed.
.TP
.B "MAGICK_ACCESS_MONITOR"
\fRWhen set to \fBTRUE\fP, command line monitor mode (enabled by
\fB-monitor\fP) will also show files accessed (including temporary
files) and any external commands which are executed. This is useful
for debugging, but also illustrates arguments made available to an
access handler registered by the
\fBMagickSetConfirmAccessHandler()\fP C library function.
.TP
.B "MAGICK_CODER_STABILITY"
\fRThe minimum coder stability level before it will be used. The
available levels are \fBPRIMARY\fP, \fBSTABLE\fP, \fBUNSTABLE\fP,
and \fBBROKEN\fP.  The default minimum level is \fBUNSTABLE\fP,
which means that all available working coders will be used. The
purpose of this option is to reduce the security exposure (or apparent
complexity) due to the huge number of formats supported. Coders at the
\fBPRIMARY\fP level are commonly used formats with very well
maintained implementations. Coders at the \fBSTABLE\fP level are
reasonably well maintained but represent less used formats. Coders at
the \fBUNSTABLE\fP level either have weak implementations, the file
format itself is weak, or the probability the coder will be needed is
vanishingly small. Coders at the \fBBROKEN\fP level are known to
often not work properly or might not be useful in their current state
at all.
.TP
.B "MAGICK_CODER_MODULE_PATH"
\fRSearch path to use when searching for image format coder modules.
This path allows the user to arbitrarily extend the image formats
supported by GraphicsMagick by adding loadable modules to an arbitrary
location rather than copying them into the GraphicsMagick installation
directory. The formatting of the search path is similar to operating
system search paths (i.e. colon delimited for Unix, and semi-colon
delimited for Microsoft Windows). This user specified search path is used
before trying the default search path.
.TP
.B "MAGICK_CONFIGURE_PATH"
\fRSearch path to use when searching for configuration (.mgk) files.
The formatting of the search path is similar to operating system search
paths (i.e. colon delimited for Unix, and semi-colon delimited for
Microsoft Windows). This user specified search path is used before trying
the default search path.
.TP
.B "MAGICK_DEBUG"
\fRDebug options (see \fB-debug\fP for details).  Setting the
configure debug option via an environment variable
(e.g. \fBMAGICK_DEBUG=configure\fP) is necessary to see the complete
initialization process, which includes searching for configuration
files.
.TP
.B "MAGICK_FILTER_MODULE_PATH"
\fRSearch path to use when searching for filter process modules
(invoked via \fB-process\fP). This path allows the user to arbitrarily
extend GraphicsMagick's image processing functionality by adding loadable
modules to an arbitrary location rather than copying them into the
GraphicsMagick installation directory. The formatting of the search path
is similar to operating system search paths (i.e. colon delimited for
Unix, and semi-colon delimited for Microsoft Windows). This user
specified search path is used before trying the default search path.
.TP
.B "MAGICK_GHOSTSCRIPT_PATH"
\fRFor Microsoft Windows, specify the path to the Ghostscript
installation rather than searching for it via the Windows registry.
This helps in case Ghostscript is not installed via the Ghostscript
Windows installer or the user wants more control over the Ghostscript
used.
.TP
.B "MAGICK_HOME"
\fRPath to top of GraphicsMagick installation directory. Only observed
by "uninstalled" builds of GraphicsMagick which do not have their location
hard-coded or set by an installer.
.TP
.B "MAGICK_MMAP_READ"
\fRIf \fBMAGICK_MMAP_READ\fP is set to \fBTRUE\fP, GraphicsMagick
will attempt to memory-map the input file for reading. This usually
substantially improves repeated read performance since the file is
already in memory after the first time it has been read. However,
testing shows that performance may be reduced for files accessed for
the first time since data is accessed via page-faults (upon first
access) and many operating systems fail to do sequential read-ahead of
memory mapped files, and particularly if those files are accessed over
a network.  If many large input files are read, then enabling this
option may harm performance by overloading the operating system's VM
system as it then needs to free unmapped pages and map new ones.
.TP
.B "MAGICK_IO_FSYNC"
\fRIf \fBMAGICK_IO_FSYNC\fP is set to \fBTRUE\fP, then GraphicsMagick
will request that the output file is fully flushed and synchronized to
disk when it is closed. This incurs a performance penalty, but has the
benefit that if the power fails or the system crashes, the file should be
valid on disk. If image files are referenced from a database, then this
option helps assure that the files referenced by the database are
valid.
.TP
.B "MAGICK_IOBUF_SIZE"
\fRThe amount of I/O buffering (in bytes) to use when reading and
writing encoded files. The default is 16384, which is observed to work
well for many cases. The best value for a local filesystem is usually the
the native filesystem block size (e.g. 4096, 8192, or even 131,072 for
ZFS) in order to minimize the number of physical disk I/O operations.
I/O performance to files accessed over a network may benefit
significantly by tuning this option. Larger values are not necessarily
better (they may be slower!), and there is rarely any benefit from using
values larger than 32768. Use convert's \fB-verbose\fP option in order
to evaluate read and write rates in pixels per second while keeping in
mind that the operating system will try to cache files in RAM.
.TP
.B "MAGICK_LIMIT_DISK"
\fRMaximum amount of disk space allowed for use by the pixel cache.
.TP
.B "MAGICK_LIMIT_FILES"
\fRMaximum number of open files.
.TP
.B "MAGICK_LIMIT_MAP"
\fRMaximum size of a memory mapped file allocation.  A memory mapped
file consumes memory when the file is accessed, although the system
may reclaim such memory when needed.
.TP
.B "MAGICK_LIMIT_MEMORY"
\fRMaximum amount of memory to allocate from the heap.
.TP
.B "MAGICK_LIMIT_PIXELS"
\fRMaximum number of total pixels (image rows times image colums) to
allow for any image which is requested to be created or read.  This is
useful to place a limit on how large an image may be.  If the input
image file has image dimensions larger than the pixel limit, then the
image memory allocation is denied and an error is returned
immediately.  This is a per-image limit and does not limit the total
number of pixels due to multiple image frames/pages (e.g. multi-page
document or an animation).
.TP
.B "MAGICK_LIMIT_READ"
\fRMaximum number of uncompressed bytes which may be read while
decoding an image.  Each read by the software from the input file is
counted against the total, even if it has been read before.  Decoding
fails when the limit is reached.  This limit helps defend against
highly compressed files (e.g. via gzip), or files which use complex
looping structures, or when data is being read from a stream
(pipe).
.TP
.B "MAGICK_LIMIT_WIDTH"
\fRMaximum pixel width of an image read, or created.
.TP
.B "MAGICK_LIMIT_HEIGHT"
\fRMaximum pixel height of an image read, or created.
.TP
.B "MAGICK_TMPDIR"
\fRPath to directory where GraphicsMagick should write temporary
files. The default is to use the system default, or the location set by
\fBTMPDIR\fP.
.TP
.B "TMPDIR"
\fRFor POSIX-compatible systems (Unix-compatible), the path to the
directory where all applications should write temporary files.
Overridden by \fBMAGICK_TMPDIR\fP if it is set.
.TP
.B "TMP \fIor TEMP"\fP
\fRFor Microsoft Windows, the path to the directory where applications
should write temporary files. Overridden by \fBMAGICK_TMPDIR\fP if it
is set.
.TP
.B "OMP_NUM_THREADS"
\fRAs per the OpenMP standard, this specifies the number of threads to
use in parallel regions. Some compilers default the number of threads to
use to the number of processor cores available while others default to
just one thread. See the OpenMP specification for other standard
adjustments and your compiler's manual for vendor-specific settings.
.SH CONFIGURATION FILES
GraphicsMagick uses a number of XML format configuration files:
.TP
.B "colors.mgk"
\fRcolors configuration file

.nf
  <?xml version="1.0"?>
  <colormap>
    <color name="AliceBlue" red="240" green="248" blue="255"
           compliance="SVG, X11, XPM" />
  </colormap>
.fi
.TP
.B "delegates.mgk"
\fRdelegates configuration file
.TP
.B "log.mgk"
\fRlogging configuration file

.nf
  <?xml version="1.0"?>
  <magicklog>
    <log events="None" />
    <log output="stdout" />
    <log filename="Magick-%d.log" />
    <log generations="3" />
    <log limit="2000" />
    <log format="%t %r %u %p %m/%f/%l/%d:\\n  %e"  />
  </magicklog>
.fi
.TP
.B "modules.mgk"
\fRloadable modules configuration file

.nf
  <?xml version="1.0"?>
  <modulemap>
    <module magick="8BIM" name="META" />
  </modulemap>
.fi
.TP
.B "type.mgk"
\fRmaster type (fonts) configuration file

.nf
  <?xml version="1.0"?>
  <typemap>
    <\fB\fPinclude file="type-windows.mgk" />
    <type
      name="AvantGarde-Book"
      fullname="AvantGarde Book"
      family="AvantGarde"
      foundry="URW"
      weight="400"
      style="normal"
      stretch="normal"
      format="type1"
      metrics="/usr/local/share/ghostscript/fonts/a010013l.afm"
      glyphs="/usr/local/share/ghostscript/fonts/a010013l.pfb"
    />
  </typemap>
.fi
.SH GM ANIMATE

\fBAnimate\fP displays a sequence of images on any workstation display
running an X server. \fBanimate\fP first determines the hardware capabilities
of the workstation. If the number of unique colors in an image is less
than or equal to the number the workstation can support, the image is displayed
in an X window. Otherwise the number of colors in the image is first reduced
to match the color resolution of the workstation before it is displayed.

This means that a continuous-tone 24 bits-per-pixel image can display on
a 8 bit pseudo-color device or monochrome device. In most instances the
reduced color image closely resembles the original. Alternatively, a monochrome
or pseudo-color image sequence can display on a continuous-tone 24 bits-per-pixel
device.

To help prevent color flashing on X server visuals that have colormaps,
\fBanimate\fP
creates a single colormap from the image sequence. This can be rather time
consuming. You can speed this operation up by reducing the colors in the
image before you "animate" them. Use \fBmogrify\fP to color reduce the
images to a single colormap. See \fBmogrify(1)\fP for details. Alternatively,
you can use a Standard Colormap; or a static, direct, or true color visual.
You can define a Standard Colormap with \fIxstdcmap\fP. See \fBxstdcmap(1)\fP
for details. This method is recommended for colormapped X server because
it eliminates the need to compute a global colormap.
.SH EXAMPLES

To animate a set of images of a cockatoo, use:

.nf
    gm animate cockatoo.*
.fi

To animate a cockatoo image sequence while using the Standard Colormap
\fIbest\fP, use:

.nf
    xstdcmap -best
    gm animate -map best cockatoo.*
.fi

To animate an image of a cockatoo without a border centered on a backdrop,
use:


.nf
    gm animate +borderwidth -backdrop cockatoo.*
.fi
.SH OPTIONS

For a more detailed description of each option, see
Options, above.

.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-backdrop"
\fRdisplay the image centered on a backdrop.
.TP
.B "-background \fI<color>"\fP
\fRthe background color
.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color
.TP
.B "-borderwidth \fI<geometry>"\fP
\fRthe border width
.TP
.B "-chop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRremove pixels from the interior of an image
.TP
.B "-colormap \fI<type>"\fP
\fRdefine the colormap type
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-delay \fI<1/100ths of a second>"\fP
\fRdisplay the next image after pausing
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text
.TP
.B "-foreground \fI<color>"\fP
\fRdefine the foreground color
.TP
.B "-gamma \fI<value>"\fP
\fRlevel of gamma correction
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-iconGeometry \fI<geometry>"\fP
\fRspecify the icon geometry
.TP
.B "-iconic"
\fRiconic animation
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-map \fI<type>"\fP
\fRdisplay image using this type.
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-mattecolor \fI<color>"\fP
\fRspecify the color to be used with the \fB-frame\fP option
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-name"
\fRname an image
.TP
.B "-noop"
\fRNOOP (no option)
.TP
.B "-pause \fI<seconds>"\fP
\fRpause between animation loops [animate]
.TP
.B "-remote"
\fRperform a X11 remote operation
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scenes \fI<value-value>"\fP
\fRrange of image scene numbers to read
.TP
.B "-shared-memory"
\fRuse shared memory
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-text-font \fI<name>"\fP
\fRfont for writing fixed-width text
.TP
.B "-title \fI<string>"\fP
\fRassign title to displayed image [\fIanimate, display, montage\fP]
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-visual \fI<type>"\fP
\fRanimate images using this X visual type
.TP
.B "-window \fI<id>"\fP
\fRmake image the background of a window

For a more detailed description of each option, see
Options, above.


Any option you specify on the command line remains in effect for the group
of images following it, until the group is terminated by the appearance of
any option or \fB-noop\fP.  For example, to animate three images, the first
with 32 colors, the second with an unlimited number of colors, and the
third with only 16 colors, use:


.nf
    gm animate -colors 32 cockatoo.1 -noop cockatoo.2
             -colors 16 cockatoo.3
.fi

\fBAnimate\fP options can appear on the command line or in your X resources
file. See \fIX(1)\fP. Options on the command line supersede values specified
in your X resources file.
Image filenames may appear in any order on the command line if the image
format is \fIMIFF\fP (refer to \fBmiff(5)\fP and the
\fBscene\fP keyword
is specified in the image. Otherwise the images will display in the order
they appear on the command line.
.SH MOUSE BUTTONS

Press any button to map or unmap the Command widget. See the next section
for more information about the Command widget.
.SH COMMAND WIDGET

The Command widget lists a number of sub-menus and commands. They are

    \fBAnimate\fP

        Open
        Play
        Step
        Repeat
        Auto Reverse

    \fBSpeed\fP

        Faster
        Slower

    \fBDirection\fP

        Forward
        Reverse

    \fBImage Info\fP
    \fBHelp\fP
    \fBQuit\fP


Menu items with a indented triangle have a sub-menu. They are represented
above as the indented items. To access a sub-menu item, move the pointer
to the appropriate menu and press a button and drag. When you find the
desired sub-menu item, release the button and the command is executed.
Move the pointer away from the sub-menu if you decide not to execute a
particular command.
.SH KEYBOARD ACCELERATORS
.in 15

.in 15
.B "\fBCtl+O\fP"
.in 20
 \fR
.in 20
Press to load an image from a file.
.in 15
.in 15
.B "\fBspace\fP"
.in 20
 \fR
.in 20
Press to display the next image in the sequence.
.in 15
.in 15
.B "\fB<\fP"
.in 20
 \fR
.in 20
Press to speed-up the display of the images.  Refer to
\fB-delay\fP for more information.
.in 15
.in 15
.B "\fB>\fP"
.in 20
 \fR
.in 20
Press to slow the display of the images.  Refer to
\fB-delay\fP for more information.
.in 15
.in 15
.B "\fB?\fP"
.in 20
 \fR
.in 20
Press to display information about the image.  Press
any key or button to erase the information.
.in 15
.in 20
This information is printed: image name;  image size;
and the total number of unique colors in the image.
.in 15
.in 15
.B "\fBF1\fP"
.in 20
 \fR
.in 20
Press to display helpful information about \fBanimate(1)\fP.
.in 15
.in 15
.B "\fBCtl-q\fP"
.in 20
 \fR
.in 20
Press to discard all images and exit program.
.in 15

.SH X RESOURCES

\fBAnimate\fP options can appear on the command line or in your X resource
file. Options on the command line supersede values specified in your X
resource file. See \fBX(1)\fP for more information on X resources.

All \fBanimate\fP options have a corresponding X resource. In addition,
the \fBanimate\fP program uses the following X resources:
.in 15

.in 15
.B "\fBbackground\fP \fB(\fP\fIclass\fP \fBBackground)\fP"
.in 20
 \fR
.in 20

Specifies the preferred color to use for the Image window background. The
default is #ccc.
.in 15
.in 15
.B "\fBborderColor\fP \fB(\fP\fIclass\fP \fBBorderColor)\fP"
.in 20
 \fR
.in 20

Specifies the preferred color to use for the Image window border. The default
is #ccc.
.in 15
.in 15
.B "\fBborderWidth\fP \fB(\fP\fIclass\fP \fBBorderWidth)\fP"
.in 20
 \fR
.in 20

Specifies the width in pixels of the Image window border. The default is
2.
.in 15
.in 15
.B "\fBfont\fP \fB(\fP\fIclass\fP \fBFont\fP \fBor\fP \fBFontList)\fP"
.in 20
 \fR
.in 20

Specifies the name of the preferred font to use in normal formatted text.
The default is 14 point \fIHelvetica\fP.
.in 15
.in 15
.B "\fBforeground\fP \fB(\fP\fIclass\fP \fBForeground)\fP"
.in 20
 \fR
.in 20

Specifies the preferred color to use for text within the Image window.
The default is black.
.in 15
.in 15
.B "\fBgeometry\fP \fB(\fP\fIclass\fP \fBgeometry)\fP"
.in 20
 \fR
.in 20

Specifies the preferred size and position of the image window. It is not
necessarily obeyed by all window managers.
Offsets, if present, are handled in \fIX(1)\fP style.  A negative x offset is
measured from the right edge of the screen to the right edge of the icon,
and a negative y offset is measured from the bottom edge of the screen
to the bottom edge of the icon.
.in 15
.in 15
.B "\fBiconGeometry\fP \fB(\fP\fIclass\fP \fBIconGeometry)\fP"
.in 20
 \fR
.in 20

Specifies the preferred size and position of the application when iconified.
It is not necessarily obeyed by all window managers.
Offsets, if present, are handled in the same manner as in class Geometry.
.in 15
.in 15
.B "\fBiconic\fP \fB(\fP\fIclass\fP \fBIconic)\fP"
.in 20
 \fR
.in 20

This resource indicates that you would prefer that the application's windows
initially not be visible as if the windows had be immediately iconified
by you. Window managers may choose not to honor the application's request.
.in 15
.in 15
.B "\fBmatteColor\fP \fB(\fP\fIclass\fP \fBMatteColor)\fP"
.in 20
 \fR
.in 20

Specify the color of windows. It is used for the backgrounds of windows,
menus, and notices. A 3D effect is achieved by using highlight and shadow
colors derived from this color. Default value: #ddd.
.in 15
.in 15
.B "\fBname\fP \fB(\fP\fIclass\fP \fBName)\fP"
.in 20
 \fR
.in 20

This resource specifies the name under which resources for the application
should be found. This resource is useful in shell aliases to distinguish
between invocations of an application, without resorting to creating links
to alter the executable file name. The default is the application name.
.in 15
.in 15
.B "\fBsharedMemory\fP \fB(\fP\fIclass\fP \fBSharedMemory)\fP"
.in 20
 \fR
.in 20

This resource specifies whether animate should attempt use shared memory
for pixmaps. ImageMagick must be compiled with shared memory support, and
the display must support the MIT-SHM extension. Otherwise, this resource
is ignored. The default is True.
.in 15
.in 15
.B "\fBtext_font\fP \fB(\fP\fIclass\fP \fBtextFont)\fP"
.in 20
 \fR
.in 20

Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text. The default is 14 point \fICourier\fP.
.in 15
.in 15
.B "\fBtitle\fP \fB(\fP\fIclass\fP \fBTitle)\fP"
.in 20
 \fR
.in 20

This resource specifies the title to be used for the Image window. This
information is sometimes used by a window manager to provide some sort
of header identifying the window. The default is the image file name.
.in 15

.SH GM BATCH
.SH DESCRIPTION

\fBbatch\fP executes an arbitary number of the utility commands
(e.g. \fBconvert\fP) in the form of a simple linear batch script in
order to improve execution efficiency, and/or to allow use as a
subordinate co-process under the control of an arbitrary script or
program.
.SH EXAMPLES
 To drive \fB'gm batch'\fP using a shell script (or a program
written in any language), have the script/program send commands to 'gm
batch' via its standard input.  Specify that standard input should be
used by using \fB'-'\fP as the file name.  The following example
converts all files matching '*.jpg' to TIFF format while rotating each
file by 90 degrees and stripping all embedded profiles.  The shell
script syntax is standard Unix shell:

.nf
  for file in *.jpg
  do
    outfile=`basename $file .jpg`.tiff
    echo convert -verbose "'$file'" -rotate 90 \\
    +profile "'*'" "'$outfile'"
  done | gm batch -echo on -feedback on -
.fi

We can accomplish the same as the previous example by putting all the
commands in a text file and then specifying the name of the text file
as the script to execute:

.nf
  for file in *.jpg
  do
    outfile=`basename $file .jpg`.tiff
    echo convert -verbose "'$file'" -rotate 90 \\
    +profile "'*'" "'$outfile'"
  done > script.txt
  gm batch -echo on -feedback on script.txt
.fi
.SH OPTIONS

Options are processed from left to right and must appear before any filename argument.
.TP
.B "-echo \fIon|off"\fP
\fRcommand echo on or off

Specify \fBon\fP to enable echoing commands to standard output as
they are read or \fBoff\fP to disable.  The default is
\fBoff\fP.
.TP
.B "-escape \fIunix|windows"\fP
\fRParse using unix or windows syntax

Commands must be parsed from the input stream and escaping needs to be
used to protect spaces or quoting characters in the input. Specify
\fBunix\fP to use unix-style command line parsing or \fBwindows\fP
for Microsoft Windows command shell style parsing. The default depends
on if the software is compiled for Microsoft Windows or for a
Unix-type system (including Cygwin on Microsoft Windows).  It is
recommended to use unix syntax because it is more powerful and more
portable.
.TP
.B "-fail \fItext"\fP
\fRtext to print if a command fails

When feedback is enabled, this specifies the text to print when the
command fails.  The default text is \fBFAIL\fP.
.TP
.B "-feedback \fIon|off"\fP
\fRenable error feedback

Print text (see -pass and -fail options) feedback after each
command to indicate the result, the default is \fBoff\fP.
.TP
.B "-help"

Prints batch command help.
.TP
.B "-pass \fItext"\fP
\fRtext to print if a command passes

When feedback is enabled, this specifies the text to print when the
command passes.  The default text is \fBPASS\fP.
.TP
.B "-prompt \fItext"\fP
\fRPrompt text to use for command line

If no filename argument was specified, a simple command prompt appears
where you may enter GraphicsMagick commands.  The default prompt is
\fBGM>\fP.  Use this option to change the prompt to something else.
.TP
.B "-stop-on-error \fIon|off"\fP
\fRSpecify if command processing stops on error

Normally command processing continues if a command encounters an
error.  Specify \fB-stop-on-error on\fP to cause processing to quit
immediately on error.
.SH GM BENCHMARK
.SH DESCRIPTION

\fBbenchmark\fP executes an arbitrary \fBgm\fP utility command
(e.g. \fBconvert\fP) for one or more loops, and/or a specified
execution time, and reports many execution metrics.  For builds using
OpenMP, a mode is provided to execute the benchmark with an increasing
number of threads and provide a report of speedup and multi-thread
execution efficiency.  If \fBbenchmark\fP is used to execute a
command without any additional benchmark options, then the command is
run once.
.SH EXAMPLES
To obtain benchmark information for a single execution of a
command:

.nf
    gm benchmark convert input.ppm -gaussian 0x1 output.ppm
.fi
To obtain benchmark information from 100 iterations of the
command:

.nf
    gm benchmark -iterations 100 convert input.ppm \\
      -gaussian 0x1 output.ppm
.fi
To obtain benchmark information by iterating the command until a
specified amount of time (in seconds) has been consumed:

.nf
    gm benchmark -duration 30 convert input.ppm \\
      -gaussian 0x1 output.ppm
.fi
To obtain a full performance report with an increasing number of
threads (1-32 threads, stepping the number of threads by four each
time):

.nf
    gm benchmark -duration 3 -stepthreads 4 convert \\
      input.ppm -gaussian 0x2 output.ppm
.fi
Here is the interpretation of the output:

    \fBthreads\fP - number of threads used.
    \fBiter\fP - number of command iterations executed.
    \fBuser\fP - total user time consumed.
    \fBtotal\fP - total elapsed time consumed.
    \fBiter/s\fP - number of command iterations per second.
    \fBiter/cpu\fP - amount of CPU time consumed per iteration.
    \fBspeedup\fP - speedup compared with one thread.
    \fBkarp-flatt\fP - Karp-Flatt measure of speedup efficiency.

\fIPlease note that the reported "speedup" is based on the
execution time of just one thread.  A preliminary warm-up pass is used
before timing the first loop in order to ensure that the CPU is
brought out of power-saving modes and that system caches are warmed
up.  Most modern CPUs provide a "turbo" mode where the CPU clock speed
is increased (e.g. by a factor of two) when only one or two cores are
active.  If the CPU grows excessively hot (due to insufficient
cooling), then it may dial back its clock rates as a form of thermal
management.  These factors result in an under-reporting of speedup
compared to if "turbo" mode was disabled and the CPU does not need to
worry about thermal management.  The \fBpowertop\fP utility available
under Linux and Solaris provides a way to observe CPU core clock rates
while a benchmark is running.\fP
.SH OPTIONS
 Options are processed from left to right and must appear before
any argument.
.TP
.B "-duration \fIduration"\fP
\fRduration to run benchmark
Specify the number of seconds to run the benchmark. The command is
executed repeatedly until the specified amount of time has
elapsed.
.TP
.B "-help"

Prints benchmark command help.
.TP
.B "-iterations \fIloops"\fP
\fRnumber of command iterations
Specify the number of iterations to run the benchmark. The command
is executed repeatedly until the specified number of iterations has
been reached.
.TP
.B "-rawcsv"
\fRPrint results in CSV format
Print results in a comma-separated value (CSV) format which is easy
to parse for plotting or importing into a spreadsheet or database.
The values reported are \fBthreads\fP, \fBiterations\fP,
\fBuser_time\fP, and \fBelapsed_time\fP.
.TP
.B "-stepthreads \fIstep"\fP
\fRexecute a per-thread benchmark ramp
 Execute a per-thread benchmark ramp, incrementing the number of
threads at each step by the specified value.  The maximum number of
threads is taken from the standard OMP_NUM_THREADS
environment variable.
.SH GM COMPARE

\fBcompare\fP compares two similar images using a specified statistical
method (see \fB-metric\fP) and/or by writing a difference image
(\fB-file\fP), with the altered pixels annotated using a specified
method (see \fB-highlight-style\fP) and color (see
\fB-highlight-color\fP). \fIReference-image\fP is the original
image and \fIcompare-image\fP is the (possibly) altered version, which
should have the same dimensions as \fIreference-image\fP.
.SH EXAMPLES

To compare two images using Mean Square Error (MSE) statistical analysis
use:

.nf
    gm compare -metric mse original.miff compare.miff
.fi

To create an annotated difference image use:

.nf
    gm compare -highlight-style assign -highlight-color purple \\
      -file diff.miff original.miff compare.miff
.fi
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect only for the image that follows.  All
options are reset to their default values after each image is read.

For a more detailed description of each option, see
Options, above.

.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-auto-orient"
\fRorient (rotate) image so it is upright
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-file \fI<filename>"\fP
\fRwrite annotated difference image to file
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-highlight-color \fI<color>"\fP
\fRpixel annotation color
.TP
.B "-highlight-style \fI<style>"\fP
\fRpixel annotation style
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-maximum-error \fI<limit>"\fP
\fRspecifies the maximum amount of total image error
.TP
.B "-metric \fI<metric>"\fP
\fRcomparison metric (MAE, MSE, PAE, PSNR, RMSE)
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string

For a more detailed description of each option, see
Options, above.

.SH GM COMPOSITE

\fBcomposite\fP composites (combines) images to create new images.
\fIbase-image\fP is the base image and \fIchange-image\fP contains the changes.
\fIouput-image\fP is the result, and normally has the same dimensions
as \fIbase-image\fP.


The optional \fImask-image\fP can be used to provide opacity information
for \fIchange-image\fP when it has none or if you want a different mask.
A mask image is typically grayscale and the same size as
\fBbase-image\fP. If \fImask-image\fP is not grayscale, it is converted
to grayscale and the resulting intensities are used as opacity
information.
.SH EXAMPLES

To composite an image of a cockatoo with a perch, use:

.nf
    gm composite cockatoo.miff perch.ras composite.miff
.fi

To compute the difference between images in a series, use:

.nf
    gm composite -compose difference series.2 series.1
              difference.miff
.fi

To composite an image of a cockatoo with a perch starting at location (100,150),
use:

.nf
    gm composite -geometry +100+150 cockatoo.miff
              perch.ras composite.miff
.fi

To tile a logo across your image of a cockatoo, use

.nf
    gm convert +shade 30x60 cockatoo.miff mask.miff
    gm composite -compose bumpmap -tile logo.png
              cockatoo.miff mask.miff composite.miff
.fi

To composite a red, green, and blue color plane into a single composite image,
try

.nf
    gm composite -compose CopyGreen green.png red.png
              red-green.png
    gm composite -compose CopyBlue blue.png red-green.png 
              gm composite.png
.fi
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect only for the image that follows.  All
options are reset to their default values after each image is read.

For a more detailed description of each option, see
Options, above.

.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-background \fI<color>"\fP
\fRthe background color
.TP
.B "-blue-primary \fI<x>,<y>"\fP
\fRblue chromaticity primary point
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment
.TP
.B "-compose \fI<operator>"\fP
\fRthe type of image composition
.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-displace \fI<horizontal scale>x<vertical scale>"\fP
\fRshift image pixels as defined by a displacement map
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dissolve \fI<percent>"\fP
\fRdissolve an image into another by the given percent
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-encoding \fI<type>"\fP
\fRspecify the text encoding
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-filter \fI<type>"\fP
\fRuse this type of filter when resizing an image
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-gravity \fI<type>"\fP
\fRdirection primitive  gravitates to when annotating the image.
.TP
.B "-green-primary \fI<x>,<y>"\fP
\fRgreen chromaticity primary point
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-negate"
\fRreplace every pixel with its complementary color
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas
.TP
.B "-profile \fI<filename>"\fP
\fRadd ICM, IPTC, or generic profile  to image
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
.TP
.B "-recolor \fI<matrix>"\fP
\fRapply a color translation matrix to image channels
.TP
.B "-red-primary \fI<x>,<y>"\fP
\fRred chromaticity primary point
.TP
.B "-render"
\fRrender vector operations
.TP
.B "-repage \fI <width>x<height>+xoff+yoff[!]"\fP
\fRAdjust image page offsets
.TP
.B "-resize \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scene \fI<value>"\fP
\fRset scene number
.TP
.B "-set \fI<attribute> <value>"\fP
\fRset an image attribute
.TP
.B "+set \fI<attribute>"\fP
\fRunset an image attribute
.TP
.B "-sharpen \fI<radius>{x<sigma>}"\fP
\fRsharpen the image
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-stegano \fI<offset>"\fP
\fRhide watermark within an image
.TP
.B "-stereo"
\fRcomposite two images to create a stereo anaglyph
.TP
.B "-strip"
\fRremove all profiles and text attributes from the image
.TP
.B "-thumbnail \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image (quickly)
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-units \fI<type>"\fP
\fRthe units of image resolution
.TP
.B "-unsharp \fI<radius>{x<sigma>}{+<amount>}{+<threshold>}"\fP
\fRsharpen the image with an unsharp mask operator
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-watermark \fI<brightness>x<saturation>"\fP
\fRpercent brightness and saturation of a watermark
.TP
.B "-white-point \fI<x>,<y>"\fP
\fRchromaticity white point
.TP
.B "-write \fI<filename>"\fP
\fRwrite an intermediate image [\fIconvert, composite\fP]

For a more detailed description of each option, see
Options, above.

.SH GM CONJURE

The Magick scripting language (MSL) will primarily benefit those that
want to accomplish custom image processing tasks but do not wish to
program, or those that do not have access to a Perl interpreter or a
compiler.  The interpreter is called conjure and here is an example
script:

.nf
    <?xml version="1.0" encoding="UTF-8"?>
    <image size="400x400" >
      <read filename="image.gif" />
      <get width="base-width" height="base-height" />
      <resize geometry="%[dimensions]" />
      <get width="width" height="height" />
      <print output=
        "Image sized from %[base-width]x%[base-height]
         to %[width]x%[height].\\n" />
      <write filename="image.png" />
    </image>
.fi

invoked with

.nf
    gm conjure -dimensions 400x400 incantation.msl
.fi

All operations will closely follow the key/value pairs defined in
PerlMagick, unless otherwise noted.
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect until it is explicitly changed by specifying
the option again with a different effect, or if it is changed by a statement
in the scripting language.

You can define your own keyword/value pairs on the command line.
The script can then use this information when setting values by including
%[keyword] in the string.  For example, if you included
"-dimensions 400x400" on the command line, as illustrated above,
then any string
containing "%[dimensions]" would have 400x400 substituted.
The "%[string]" can be used either an entire string, such as
geometry="%[dimensions]" or as a part of a string such as
filename="%[basename].png".

The keyword can be any string except for the following reserved
strings (in any upper, lower, or mixed case variant): \fBdebug\fP,
\fBhelp\fP, and \fBverbose\fP, whose usage is described below.

The value can be any string.  If
either the keyword or the value contains white space or any
symbols that have special meanings to your shell such as "#",
"|",
or
"%", enclose the string in quotation marks or use "\\" to escape the white
space and special symbols.

Keywords and values are case dependent.  "Key",
"key",
and "KEY" would
be three different keywords.

For a more detailed description of each option, see
Options, above.

.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.SH MAGICK SCRIPTING LANGUAGE

The Magick Scripting Language (MSL) presently defines the following
elements and their attributes:
.in 15

.in 15
.B "<image>"
.in 20
 \fR
.in 20
background, color, id, size
.in 15
.in 20

Define a new image object.  \fB</image>\fP destroys it. Because of
this, if you wish to reference multiple "subimages" (aka pages or
layers), you can embed one \fBimage\fP element inside of another. For
example:

.in 15
.in 20


.nf
    <image>
    <read filename="input.png" />
    <get width="base-width" height="base-height" />
    <image height="base-height" width="base-width">
    <image />
    <write filename="output.mng" />
    </image>
.fi

.in 15
.in 20


.nf
    <image size="400x400" />
.fi

.in 15
.in 15
.B "<group>"
.in 20
 \fR
.in 20

Define a new group of image objects.  By default, images are only
valid for the life of their \fB<image>\fPelement.

.in 15
.in 20


.nf
    <image>   -- creates the image
    .....     -- do stuff with it
    </image>  -- dispose of the image
.fi

.in 15
.in 20

However, in a group, all images in that group will stay around for the
life of the group:

.in 15
.in 20


.nf
    <group>                           -- start a group
        <image>                       -- create an image
        ....                          -- do stuff
        </image>                      -- NOOP
        <image>                       -- create another image
        ....                          -- do more stuff
        </image>                      -- NOOP
        <write filename="image.mng" />  -- output
    </group>                          -- dispose of both images
.fi

.in 15
.in 15
.B "<read>"
.in 20
 \fR
.in 20
    filename
.in 15
.in 20

Read a new image from a disk file.

.in 15
.in 20


.nf
    <read filename="image.gif" />
.fi

.in 15
.in 20

To read two images use

.in 15
.in 20


.nf
    <read filename="image.gif" />
    <read filename="image.png />
.fi

.in 15
.in 15
.B "<write>"
.in 20
 \fR
.in 20
    filename
.in 15
.in 20
Write the image(s) to disk, either as
a single multiple-image file or multiple ones if necessary.

.in 15
.in 20


.nf
     <write filename=image.tiff" />
.fi
.in 15
.B "<get>"
.in 20
 \fR
.in 20
Get any attribute recognized by
PerlMagick's GetAttribute() and stores it as an image attribute for later
use. Currently only \fIwidth\fP and \fIheight\fP are supported.
.in 15
.in 20


.nf
    <get width="base-width" height="base-height" />
    <print output="Image size is %[base-width]x%[base-height].\\n" />
.fi

.in 15
.in 15
.B "<set>"
.in 20
 \fR
.in 20
background, bordercolor, clip-mask, colorspace, density,
magick, mattecolor, opacity.  Set an attribute recognized by
PerlMagick's GetAttribute().
.in 15
.in 15
.B "<profile>"
.in 20
 \fR
.in 20
    [profilename]
.in 15
.in 20

Read one or more IPTC, ICC or generic profiles from file and assign to image

.in 15
.in 20


.nf
    <profile iptc="profile.iptc" generic="generic.dat" />
.fi

.in 15
.in 20

To remove a specified profile use "!" as the filename eg

.in 15
.in 20


.nf
    <profile icm="!" iptc="profile.iptc" />
.fi

.in 15
.in 15
.B "<border>"
.in 20
 \fR
.in 20
    fill, geometry, height, width
.in 15
.in 15
.B "<blur>"
.in 20
 \fR
.in 20
    radius, sigma
.in 15
.in 15
.B "<charcoal>"
.in 20
 \fR
.in 20
    radius, sigma
.in 15
.in 15
.B "<chop>"
.in 20
 \fR
.in 20
    geometry, height, width, x, y
.in 15
.in 15
.B "<crop>"
.in 20
 \fR
.in 20
    geometry, height, width, x, y
.in 15
.in 15
.B "<composite>"
.in 20
 \fR
.in 20
    compose, geometry, gravity, image, x, y
.in 15
.in 20


.nf
    <?xml version="1.0" encoding="UTF-8"?>
    <group>
        <image id="image_01">
            <read filename="cloud3.gif"/>
            <resize geometry="250x90"/>
        </image>
        <image id="image_02">
            <read filename="cloud4.gif"/>
            <resize geometry="190x100"/>
        </image>
        <image>
            <read filename="background.jpg"/>
            <composite image="image_01" geometry="+740+470"/>
            <composite image="image_02" geometry="+390+415"/>
        </image>
        <write filename="result.png"/>
    </group>
.fi

.in 15
.in 15
.B "<despeckle>"
.in 20
 \fR
.in 15
.B "<emboss>"
.in 20
 \fR
.in 20
    radius, sigma
.in 15
.in 15
.B "<enhance>"
.in 20
 \fR
.in 15
.B "<equalize>"
.in 20
 \fR
.in 15
.B "<edge>"
.in 20
 \fR
.in 20
    radius
.in 15
.in 15
.B "<flip>"
.in 20
 \fR
.in 15
.B "<flop>"
.in 20
 \fR
.in 15
.B "<frame>"
.in 20
 \fR
.in 20
    fill, geometry, height, width, x, y, inner, outer
.in 15
.in 15
.B "<flatten>"
.in 20
 \fR
.in 15
.B "<get>"
.in 20
 \fR
.in 20
    height, width
.in 15
.in 15
.B "<gamma>"
.in 20
 \fR
.in 20
    red, green, blue
.in 15
.in 15
.B "<image>"
.in 20
 \fR
.in 20
    background, color, id, size
.in 15
.in 15
.B "<implode>"
.in 20
 \fR
.in 20
    amount
.in 15
.in 15
.B "<magnify>"
.in 20
 \fR
.in 15
.B "<minify>"
.in 20
 \fR
.in 15
.B "<medianfilter>"
.in 20
 \fR
.in 20
    radius
.in 15
.in 15
.B "<normalize>"
.in 20
 \fR
.in 15
.B "<oilpaint>"
.in 20
 \fR
.in 20
    radius
.in 15
.in 15
.B "<print>"
.in 20
 \fR
.in 20
    output
.in 15
.in 15
.B "<profile>"
.in 20
 \fR
.in 20
    [profilename]
.in 15
.in 15
.B "<read>"
.in 20
 \fR
.in 15
.B "<resize>"
.in 20
 \fR
.in 20
    blur, filter, geometry, height, width
.in 15
.in 15
.B "<roll>"
.in 20
 \fR
.in 20
    geometry, x, y
.in 15
.in 15
.B "<rotate>"
.in 20
 \fR
.in 20
    degrees
.in 15
.in 15
.B "<reducenoise>"
.in 20
 \fR
.in 20
    radius
.in 15
.in 15
.B "<sample>"
.in 20
 \fR
.in 20
    geometry, height, width
.in 15
.in 15
.B "<scale>"
.in 20
 \fR
.in 20
    geometry, height, width
.in 15
.in 15
.B "<sharpen>"
.in 20
 \fR
.in 20
    radius, sigma
.in 15
.in 15
.B "<shave>"
.in 20
 \fR
.in 20
    geometry, height, width
.in 15
.in 15
.B "<shear>"
.in 20
 \fR
.in 20
    x, y
.in 15
.in 15
.B "<solarize>"
.in 20
 \fR
.in 20
    threshold
.in 15
.in 15
.B "<spread>"
.in 20
 \fR
.in 20
    radius
.in 15
.in 15
.B "<stegano>"
.in 20
 \fR
.in 20
    image
.in 15
.in 15
.B "<stereo>"
.in 20
 \fR
.in 20
    image
.in 15
.in 15
.B "<swirl>"
.in 20
 \fR
.in 20
    degrees
.in 15
.in 15
.B "<texture>"
.in 20
 \fR
.in 20
    image
.in 15
.in 15
.B "<threshold>"
.in 20
 \fR
.in 20
    threshold
.in 15
.in 15
.B "<transparent>"
.in 20
 \fR
.in 20
    color
.in 15
.in 15
.B "<trim>"
.in 20
 \fR

.SH GM CONVERT

\fBConvert\fP converts an input file using one image format to an output
file with a differing image format. In addition, various types of image
processing can be performed on the converted image during the conversion
process. \fBConvert\fP recognizes the image formats listed in
\fIGraphicsMagick(1)\fP.

.SH EXAMPLES

To make a thumbnail of a JPEG image, use:

.nf
    gm convert -size 120x120 cockatoo.jpg -resize 120x120
            +profile "*" thumbnail.jpg
.fi

In this example, '-size 120x120' gives a hint to the JPEG decoder
that the image is going to be downscaled to 120x120, allowing it to run
faster by avoiding returning full-resolution images to GraphicsMagick for
the subsequent resizing operation.  The
\'-resize 120x120' specifies the desired dimensions of the
output image.  It will be scaled so its largest dimension is 120 pixels.  The
\'+profile "*"' removes any ICM, EXIF, IPTC, or other profiles
that might be present in the input and aren't needed in the thumbnail.

To convert a \fIMIFF\fP image of a cockatoo to a SUN raster image, use:

.nf
    gm convert cockatoo.miff sun:cockatoo.ras
.fi

To convert a multi-page \fIPostScript\fP document to individual FAX pages,
use:

.nf
    gm convert -monochrome document.ps fax:page
.fi

To convert a TIFF image to a \fIPostScript\fP A4 page with the image in
the lower left-hand corner, use:

.nf
    gm convert -page A4+0+0 image.tiff document.ps
.fi

To convert a raw Gray image with a 128 byte header to a portable graymap,
use:

.nf
    gm convert -depth 8 -size 768x512+128 gray:raw
            image.pgm
.fi

In this example, "raw" is the input file.  Its format is "gray" and it
has the dimensions and number of header bytes specified by the -size
option and the sample depth specified by the
-depth option.  The output file is "image.pgm".  The suffix ".pgm"
specifies its format.

To convert a Photo CD image to a TIFF image, use:

.nf
    gm convert -size 1536x1024 img0009.pcd image.tiff
    gm convert img0009.pcd[4] image.tiff
.fi

To create a visual image directory of all your JPEG images, use:

.nf
    gm convert 'vid:*.jpg' directory.miff
.fi

To annotate an image with blue text using font 12x24 at position (100,100),
use:

.nf
    gm convert -font helvetica -fill blue
            -draw "text 100,100 Cockatoo"
            bird.jpg bird.miff
.fi

To tile a 640x480 image with a JPEG texture with bumps use:

.nf
    gm convert -size 640x480 tile:bumps.jpg tiled.png
.fi

To surround an icon with an ornamental border to use with Mosaic(1), use:

.nf
    gm convert -mattecolor "#697B8F" -frame 6x6 bird.jpg
            icon.png
.fi

To create a MNG animation from a DNA molecule sequence, use:

.nf
    gm convert -delay 20 dna.* dna.mng
.fi
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images that follows,
until the set is terminated by the appearance of any option or \fB-noop\fP.
Some options only affect the decoding of images and others only the encoding.
The latter can appear after the final group of input images.

For a more detailed description of each option, see
Options, above.

.TP
.B "-adjoin"
\fRjoin images into a single multi-image file
.TP
.B "-affine \fI<matrix>"\fP
\fRdrawing transform matrix
.TP
.B "-antialias"
\fRremove pixel aliasing
.TP
.B "-append"
\fRappend a set of images
.TP
.B "-asc-cdl \fI<spec>"\fP
\fRapply ASC CDL color transform
.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-auto-orient"
\fRorient (rotate) image so it is upright
.TP
.B "-average"
\fRaverage a set of images
.TP
.B "-background \fI<color>"\fP
\fRthe background color
.TP
.B "-black-threshold \fIred[,green][,blue][,opacity]"\fP
\fRpixels below the threshold become black
.TP
.B "-blue-primary \fI<x>,<y>"\fP
\fRblue chromaticity primary point
.TP
.B "-blur \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator
.TP
.B "-border \fI<width>x<height>"\fP
\fRsurround the image with a border of color
.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color
.TP
.B "-box \fI<color>"\fP
\fRset the color of the annotation bounding box
.TP
.B "-channel \fI<type>"\fP
\fRthe type of channel
.TP
.B "-charcoal \fI<factor>"\fP
\fRsimulate a charcoal drawing
.TP
.B "-chop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRremove pixels from the interior of an image
.TP
.B "-clip"
\fRapply the clipping path, if one is present
.TP
.B "-coalesce"
\fRmerge a sequence of images
.TP
.B "-colorize \fI<value>"\fP
\fRcolorize the image with the pen color
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment
.TP
.B "-compose \fI<operator>"\fP
\fRthe type of image composition
.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression
.TP
.B "-contrast"
\fRenhance or reduce the image contrast
.TP
.B "-convolve \fI<kernel>"\fP
\fRconvolve image with the specified convolution kernel
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image
.TP
.B "-cycle \fI<amount>"\fP
\fRdisplace image colormap by amount
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-deconstruct"
\fRbreak down an image sequence into constituent parts
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-delay \fI<1/100ths of a second>"\fP
\fRdisplay the next image after pausing
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-despeckle"
\fRreduce the speckles within an image
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-draw \fI<string>"\fP
\fRannotate an image with one or more graphic primitives
.TP
.B "-edge \fI<radius>"\fP
\fRdetect edges within an image
.TP
.B "-emboss \fI<radius>"\fP
\fRemboss an image
.TP
.B "-encoding \fI<type>"\fP
\fRspecify the text encoding
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-enhance"
\fRapply a digital filter to enhance a noisy image
.TP
.B "-equalize"
\fRperform histogram equalization to the image
.TP
.B "-extent \fI<width>x<height>{+-}<x>{+-}<y>"\fP
\fRcomposite image on background color canvas image
.TP
.B "-fill \fI<color>"\fP
\fRcolor to use when filling a graphic primitive
.TP
.B "-filter \fI<type>"\fP
\fRuse this type of filter when resizing an image
.TP
.B "-flatten"
\fRflatten a sequence of images
.TP
.B "-flip"
\fRcreate a "mirror image"
.TP
.B "-flop"
\fRcreate a "mirror image"
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text
.TP
.B "-format \fI<string>"\fP
\fRoutput formatted image characteristics
.TP
.B "-frame \fI<width>x<height>+<outer bevel width>+<inner bevel width>"\fP
\fRsurround the image with an ornamental border
.TP
.B "-fuzz \fI<distance>{%}"\fP
\fRcolors within this Euclidean distance are considered equal
.TP
.B "-gamma \fI<value>"\fP
\fRlevel of gamma correction
.TP
.B "-gaussian \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-gravity \fI<type>"\fP
\fRdirection primitive  gravitates to when annotating the image.
.TP
.B "-green-primary \fI<x>,<y>"\fP
\fRgreen chromaticity primary point
.TP
.B "-hald-clut \fI<clut>"\fP
\fRapply a Hald CLUT to the image
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-implode \fI<factor>"\fP
\fRimplode image pixels about the center
.TP
.B "-intent \fI<type>"\fP
\fRuse this type of rendering intent when managing the image color
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image
.TP
.B "-lat \fI<width>x<height>{+-}<offset>{%}"\fP
\fRperform local adaptive thresholding
.TP
.B "-level \fI<black_point>{,<gamma>}{,<white_point>}{%}"\fP
\fRadjust the level of image contrast
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-list \fI<type>"\fP
\fRthe type of list
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-loop \fI<iterations>"\fP
\fRadd Netscape loop extension to your GIF animation
.TP
.B "-magnify"
\fRmagnify the image
.TP
.B "-map \fI<filename>"\fP
\fRchoose a particular set of colors from this image
.TP
.B "-mask \fI<filename>"\fP
\fRSpecify a clipping mask
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-mattecolor \fI<color>"\fP
\fRspecify the color to be used with the \fB-frame\fP option
.TP
.B "-median \fI<radius>"\fP
\fRapply a median filter to the image
.TP
.B "-minify \fI<factor>"\fP
\fRminify the image
.TP
.B "-modulate \fIbrightness[,saturation[,hue]]"\fP
\fRvary the brightness, saturation, and hue of an image
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-morph \fI<frames>"\fP
\fRmorphs an image sequence
.TP
.B "-mosaic"
\fRcreate a mosaic from an image or an image sequence
.TP
.B "-motion-blur \fI<radius>{x<sigma>}{+angle}"\fP
\fRSimulate motion blur
.TP
.B "-negate"
\fRreplace every pixel with its complementary color
.TP
.B "-noise \fI<radius|type>"\fP
\fRadd or reduce noise in an image
.TP
.B "-noop"
\fRNOOP (no option)
.TP
.B "-normalize"
\fRtransform image to span the full range of color values
.TP
.B "-opaque \fI<color>"\fP
\fRchange this color to the pen color within the image
.TP
.B "-operator \fIchannel operator rvalue[%]"\fP
\fRapply a mathematical, bitwise, or value operator to an image channel
.TP
.B "-ordered-dither \fI<channeltype> <NxN>"\fP
\fRordered dither the image
.TP
.B "-orient \fI<orientation>"\fP
\fRSet the image orientation attribute
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas
.TP
.B "-paint \fI<radius>"\fP
\fRsimulate an oil painting
.TP
.B "-pen \fI<color>"\fP
\fR(This option has been replaced by the -fill option)
.TP
.B "-ping"
\fRefficiently determine image characteristics
.TP
.B "-pointsize \fI<value>"\fP
\fRpointsize of the PostScript, X11, or TrueType font
.TP
.B "-preview \fI<type>"\fP
\fRimage preview type
.TP
.B "-process \fI<command>"\fP
\fRprocess a sequence of images using a process module
.TP
.B "-profile \fI<filename>"\fP
\fRadd ICM, IPTC, or generic profile  to image
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
.TP
.B "-raise \fI<width>x<height>"\fP
\fRlighten or darken image edges
.TP
.B "-random-threshold \fI<channeltype> <LOWxHIGH>"\fP
\fRrandom threshold the image
.TP
.B "-recolor \fI<matrix>"\fP
\fRapply a color translation matrix to image channels
.TP
.B "-red-primary \fI<x>,<y>"\fP
\fRred chromaticity primary point
.TP
.B "-region \fI<width>x<height>{+-}<x>{+-}<y>"\fP
\fRapply options to a portion of the image
.TP
.B "-render"
\fRrender vector operations
.TP
.B "-repage \fI <width>x<height>+xoff+yoff[!]"\fP
\fRAdjust image page offsets
.TP
.B "-resample \fI<horizontal>x<vertical>"\fP
\fRResample image to specified horizontal and vertical resolution
.TP
.B "-resize \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image
.TP
.B "-roll \fI{+-}<x>{+-}<y>"\fP
\fRroll an image vertically or horizontally
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sample \fI<geometry>"\fP
\fRscale image using pixel sampling
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scale \fI<geometry>"\fP
\fRscale the image.
.TP
.B "-scene \fI<value>"\fP
\fRset scene number
.TP
.B "-set \fI<attribute> <value>"\fP
\fRset an image attribute
.TP
.B "+set \fI<attribute>"\fP
\fRunset an image attribute
.TP
.B "-segment \fI<cluster threshold>x<smoothing threshold>"\fP
\fRsegment an image
.TP
.B "-shade \fI<azimuth>x<elevation>"\fP
\fRshade the image using a distant light source
.TP
.B "-sharpen \fI<radius>{x<sigma>}"\fP
\fRsharpen the image
.TP
.B "-shave \fI<width>x<height>{%}"\fP
\fRshave pixels from the image edges
.TP
.B "-shear \fI<x degrees>x<y degrees>"\fP
\fRshear the image along the X or Y axis
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-solarize \fI<factor>"\fP
\fRnegate all pixels above the threshold level
.TP
.B "-spread \fI<amount>"\fP
\fRdisplace image pixels by a random amount
.TP
.B "-strip"
\fRremove all profiles and text attributes from the image
.TP
.B "-stroke \fI<color>"\fP
\fRcolor to use when stroking a graphic primitive
.TP
.B "-strokewidth \fI<value>"\fP
\fRset the stroke width
.TP
.B "-swirl \fI<degrees>"\fP
\fRswirl image pixels about the center
.TP
.B "-texture \fI<filename>"\fP
\fRname of texture to tile onto the image background
.TP
.B "-threshold \fI<value>{%}"\fP
\fRthreshold the image
.TP
.B "-thumbnail \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image (quickly)
.TP
.B "-tile \fI<filename>"\fP
\fRtile image when filling a graphic primitive
.TP
.B "-transform"
\fRtransform the image
.TP
.B "-transparent \fI<color>"\fP
\fRmake this color transparent within the image
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-units \fI<type>"\fP
\fRthe units of image resolution
.TP
.B "-unsharp \fI<radius>{x<sigma>}{+<amount>}{+<threshold>}"\fP
\fRsharpen the image with an unsharp mask operator
.TP
.B "-use-pixmap"
\fRuse the pixmap
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-view \fI<string>"\fP
\fRFlashPix viewing parameters
.TP
.B "-virtual-pixel \fI<method>"\fP
\fRspecify contents of "virtual pixels"
.TP
.B "-wave \fI<amplitude>x<wavelength>"\fP
\fRalter an image along a sine wave
.TP
.B "-white-point \fI<x>,<y>"\fP
\fRchromaticity white point
.TP
.B "-white-threshold \fIred[,green][,blue][,opacity]"\fP
\fRpixels above the threshold become white
.TP
.B "-write \fI<filename>"\fP
\fRwrite an intermediate image [\fIconvert, composite\fP]

For a more detailed description of each option, see
Options, above.
.SH GM DISPLAY

Display is a machine architecture independent
image processing and display program. It can display an image on any workstation
screen running an X server. \fBDisplay\fP can read and write
\fBmany\fP
of the more popular image formats (e.g. \fBJPEG\fP,
\fBTIFF\fP,
\fBPNM\fP,
\fBPhoto
CD\fP, etc.).

With \fBdisplay\fP, you can perform these functions on an image:
.in 15

 o  load an image from a file
 o  display the next image
 o  display the former image
 o  display a sequence of images as a slide show
 o  write the image to a file
 o  print the image to a \fIPostScript\fP printer
 o  delete the image file
 o  create a Visual Image Directory
 o  select the image to display by its thumbnail rather than name
 o  undo last image transformation
 o  copy a region of the image
 o  paste a region to the image
 o  restore the image to its original size
 o  refresh the image
 o  half the image size
 o  double the image size
 o  resize the image
 o  crop the image
 o  cut the image
 o  flop image in the horizontal direction
 o  flip image in the vertical direction
 o  rotate the image 90 degrees clockwise
 o  rotate the image 90 degrees counter-clockwise
 o  rotate the image
 o  shear the image
 o  roll the image
 o  trim the image edges
 o  invert the colors of the image
 o  vary the color brightness
 o  vary the color saturation
 o  vary the image hue
 o  gamma correct the image
 o  sharpen the image contrast
 o  dull the image contrast
 o  perform histogram equalization on the image
 o  perform histogram normalization on the image
 o  negate the image colors
 o  convert the image to grayscale
 o  set the maximum number of unique colors in the image
 o  reduce the speckles within an image
 o  eliminate peak noise from an image
 o  detect edges within the image
 o  emboss an image
 o  segment the image by color
 o  simulate an oil painting
 o  simulate a charcoal drawing
 o  annotate the image with text
 o  draw on the image
 o  edit an image pixel color
 o  edit the image matte information
 o  composite an image with another
 o  add a border to the image
 o  surround image with an ornamental border
 o  apply image processing techniques to a region of interest
 o  display information about the image
 o  zoom a portion of the image
 o  show a histogram of the image
 o  display image to background of a window
 o  set user preferences
 o  display information about this program
 o  discard all images and exit program
 o  change the level of magnification
 o  display images specified by a World Wide Web (WWW) uniform resource locator (URL)

.SH EXAMPLES

To scale an image of a cockatoo to exactly 640 pixels in width and 480
pixels in height and position the window at location (200,200), use:

.nf
    gm display -geometry 640x480+200+200! cockatoo.miff
.fi

To display an image of a cockatoo without a border centered on a backdrop,
use:

.nf
    gm display +borderwidth -backdrop cockatoo.miff
.fi

To tile a slate texture onto the root window, use:

.nf
    gm display -size 1280x1024 -window root slate.png
.fi

To display a visual image directory of all your JPEG images, use:

.nf
    gm display 'vid:*.jpg'
.fi

To display a MAP image that is 640 pixels in width and 480 pixels in height
with 256 colors, use:

.nf
    gm display -size 640x480+256 cockatoo.map
.fi

To display an image of a cockatoo specified with a \fBWorld Wide Web (WWW)\fP
uniform resource locator \fB(URL)\fP, use:

.nf
    gm display ftp://wizards.dupont.com/images/cockatoo.jpg
.fi

To display histogram of an image, use:

.nf
    gm gm convert file.jpg HISTOGRAM:- | gm display -
.fi
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect until it is explicitly changed by specifying
the option again with a different effect. For example to display three images,
the first with 32 colors, the second with an unlimited number of colors,
and the third with only 16 colors, use:

.nf
    gm display -colors 32 cockatoo.miff -noop duck.miff
                 -colors 16 macaw.miff
.fi

\fBDisplay\fP options can appear on the command line or in your X resources
file. See \fIX(1)\fP. Options on the command line supersede values specified
in your X resources file.

For a more detailed description of each option, see
Options, above.

.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-backdrop"
\fRdisplay the image centered on a backdrop.
.TP
.B "-background \fI<color>"\fP
\fRthe background color
.TP
.B "-border \fI<width>x<height>"\fP
\fRsurround the image with a border of color
.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color
.TP
.B "-borderwidth \fI<geometry>"\fP
\fRthe border width
.TP
.B "-colormap \fI<type>"\fP
\fRdefine the colormap type
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment
.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression
.TP
.B "-contrast"
\fRenhance or reduce the image contrast
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-delay \fI<1/100ths of a second>"\fP
\fRdisplay the next image after pausing
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-despeckle"
\fRreduce the speckles within an image
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-edge \fI<radius>"\fP
\fRdetect edges within an image
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-enhance"
\fRapply a digital filter to enhance a noisy image
.TP
.B "-filter \fI<type>"\fP
\fRuse this type of filter when resizing an image
.TP
.B "-flip"
\fRcreate a "mirror image"
.TP
.B "-flop"
\fRcreate a "mirror image"
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text
.TP
.B "-foreground \fI<color>"\fP
\fRdefine the foreground color
.TP
.B "-frame \fI<width>x<height>+<outer bevel width>+<inner bevel width>"\fP
\fRsurround the image with an ornamental border
.TP
.B "-gamma \fI<value>"\fP
\fRlevel of gamma correction
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-iconGeometry \fI<geometry>"\fP
\fRspecify the icon geometry
.TP
.B "-iconic"
\fRiconic animation
.TP
.B "-immutable"
\fRmake image immutable
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-magnify \fI<factor>"\fP
\fRmagnify the image
.TP
.B "-map \fI<type>"\fP
\fRdisplay image using this type.
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-mattecolor \fI<color>"\fP
\fRspecify the color to be used with the \fB-frame\fP option
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-name"
\fRname an image
.TP
.B "-negate"
\fRreplace every pixel with its complementary color
.TP
.B "-noop"
\fRNOOP (no option)
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas
.TP
.B "+progress"
\fRdisable progress monitor and busy cursor
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
.TP
.B "-raise \fI<width>x<height>"\fP
\fRlighten or darken image edges
.TP
.B "-remote"
\fRperform a X11 remote operation
.TP
.B "-roll \fI{+-}<x>{+-}<y>"\fP
\fRroll an image vertically or horizontally
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sample \fI<geometry>"\fP
\fRscale image using pixel sampling
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scenes \fI<value-value>"\fP
\fRrange of image scene numbers to read
.TP
.B "-set \fI<attribute> <value>"\fP
\fRset an image attribute
.TP
.B "+set \fI<attribute>"\fP
\fRunset an image attribute
.TP
.B "-segment \fI<cluster threshold>x<smoothing threshold>"\fP
\fRsegment an image
.TP
.B "-shared-memory"
\fRuse shared memory
.TP
.B "-sharpen \fI<radius>{x<sigma>}"\fP
\fRsharpen the image
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-text-font \fI<name>"\fP
\fRfont for writing fixed-width text
.TP
.B "-texture \fI<filename>"\fP
\fRname of texture to tile onto the image background
.TP
.B "-title \fI<string>"\fP
\fRassign title to displayed image [\fIanimate, display, montage\fP]
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-update \fI<seconds>"\fP
\fR
detect when image file is modified and redisplay.
.TP
.B "-use-pixmap"
\fRuse the pixmap
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-visual \fI<type>"\fP
\fRanimate images using this X visual type
.TP
.B "-window \fI<id>"\fP
\fRmake image the background of a window
.TP
.B "-window-group"
\fRspecify the window group
.TP
.B "-write \fI<filename>"\fP
\fRwrite the image to a file [\fIdisplay\fP]

For a more detailed description of each option, see
Options, above.

.SH MOUSE BUTTONS

The effects of each button press is described below. Three buttons are
required. If you have a two button mouse, button 1 and 3 are returned.
Press \fBALT\fP and button 3 to simulate button 2.
.TP
.B "1"
\fR
Press this button to map or unmap the Command
widget . See the next section for more information about the Command
widget.
.TP
.B "2"
\fR
Press and drag to define a region of the image to magnify.
.TP
.B "3"
\fR
Press and drag to choose from a select set of \fBdisplay(1)\fP
commands. This button behaves differently if the image being displayed
is a visual image directory. Choose a particular tile of the directory
and press this button and drag to select a command from a pop-up menu.
Choose from these menu items:

    Open
    Next
    Former
    Delete
    Update


If you choose \fBOpen\fP, the image represented by the tile is displayed.
To return to the visual image directory, choose \fBNext\fP from the Command
widget (refer to Command Widget).
\fBNext\fP and \fBFormer\fP
moves to the next or former image respectively. Choose \fBDelete\fP to
delete a particular image tile. Finally, choose \fBUpdate\fP to synchronize
all the image tiles with their respective images. See
montage
and
miff for more details.
.SH COMMAND WIDGET

The Command widget lists a number of sub-menus and commands. They are

    \fBFile\fP

    Open...
    Next
    Former
    Select...
    Save...
    Print...
    Delete...
    Canvas...
    Visual Directory...
    Quit



    \fBEdit\fP

    Undo
    Redo
    Cut
    Copy
    Paste



    \fBView\fP

    Half Size
    Original Size
    Double Size
    Resize...
    Apply
    Refresh
    Restore



    \fBTransform\fP

    Crop
    Chop
    Flop
    Flip
    Rotate Right
    Rotate Left
    Rotate...
    Shear...
    Roll...
    Trim Edges



    \fBEnhance\fP

    Hue...
    Saturation...
    Brightness...
    Gamma...
    Spiff...
    Dull
    Equalize
    Normalize
    Negate
    GRAYscale
    Quantize...



    \fBEffects\fP

    Despeckle
    Emboss
    Reduce Noise
    Add Noise
    Sharpen...
    Blur...
    Threshold...
    Edge Detect...
    Spread...
    Shade...
    Raise...
    Segment...



    \fBF/X\fP

    Solarize...
    Swirl...
    Implode...
    Wave...
    Oil Paint...
    Charcoal Draw...



    \fBImage Edit\fP

    Annotate...
    Draw...
    Color...
    Matte...
    Composite...
    Add Border...
    Add Frame...
    Comment...
    Launch...
    Region of Interest...



    \fBMiscellany\fP

    Image Info
    Zoom Image
    Show Preview...
    Show Histogram
    Show Matte
    Background...
    Slide Show
    Preferences...



    \fBHelp\fP

    Overview
    Browse Documentation
    About Display



Menu items with a indented triangle have a sub-menu. They are represented
above as the indented items. To access a sub-menu item, move the pointer
to the appropriate menu and press button 1 and drag. When you find the
desired sub-menu item, release the button and the command is executed.
Move the pointer away from the sub-menu if you decide not to execute a
particular command.
.SH KEYBOARD ACCELERATORS

Accelerators are one or two key presses that effect a particular command.
The keyboard accelerators that
\fBdisplay\fP understands is:

.nf
    Ctl+O     Press to load an image from a file.
    space     Press to display the next image.
.fi

If the image is a multi-paged document such as a
\fIPostScript\fP document,
you can skip ahead several pages by preceding this command with a number.
For example to display the fourth page beyond the current page,
press 4space.

.nf
    backspace Press to display the former image.
.fi

If the image is a multi-paged document such as a
\fIPostScript\fP document,
you can skip behind several pages by preceding this command with a number.
For example to display the fourth page preceding the current page, press
4n.

.nf
    Ctl-S    Press to save the image to a file.
    Ctl-P    Press to print the image to a
             \fIPostScript\fP printer.
    Ctl-D    Press to delete an image file.
    Ctl-N    Press to create a blank canvas.
    Ctl-Q    Press to discard all images and exit program.
    Ctl+Z    Press to undo last image transformation.
    Ctl+R    Press to redo last image transformation.
    Ctl-X    Press to cut a region of
             the image.
    Ctl-C    Press to copy a region of
             the image.
    Ctl-V    Press to paste a region to
             the image.
    <        Press to halve the image size.
    .        Press to return to the original image size.
    >        Press to double the image size.
    %        Press to resize the image to a width and height
             you specify.
    Cmd-A    Press to make any image transformations
             permanent.
             By default, any image size transformations are
             applied to the original image to create the
             image displayed on the X server.  However, the
             transformations are not permanent (i.e. the
             original image does not change size only the
             X image does). For example, if you press ">"
             the X image will appear to double in size, but
             the original image will in fact remain the same
             size.  To force the original image to double in
             size, press ">" followed by "Cmd-A".
    @        Press to refresh the image window.
    C        Press to crop the image.
    [        Press to chop the image.
    H        Press to flop image in the horizontal direction.
    V        Press to flip image in the vertical direction.
    /        Press to rotate the image 90 degrees clockwise.
    \\        Press to rotate the image 90 degrees
             counter-clockwise.
    *        Press to rotate the image
             the number of degrees you specify.
    S        Press to shear the image the number of degrees
             you specify.
    R        Press to roll the image.
    T        Press to trim the image edges.
    Shft-H   Press to vary the color hue.
    Shft-S   Press to vary the color saturation.
    Shft-L   Press to vary the image brightness.
    Shft-G   Press to gamma correct the image.
    Shft-C   Press to spiff up the image contrast.
    Shft-Z   Press to dull the image contrast.
    =        Press to perform histogram equalization on
             the image.
    Shft-N   Press to perform histogram normalization on
             the image.
    Shft-~   Press to negate the colors of the image.
    .        Press to convert the image colors to gray.
    Shft-#   Press to set the maximum number of unique
             colors in the image.
    F2       Press to reduce the speckles in an image.
    F2       Press to emboss an image.
    F4       Press to eliminate peak noise from an image.
    F5       Press to add noise to an image.
    F6       Press to sharpen an image.
    F7       Press to blur image an image.
    F8       Press to threshold the image.
    F9       Press to detect edges within an image.
    F10      Press to displace pixels by a random amount.
    F11      Press to shade the image using a distant light
             source.
    F12      Press to lighten or darken image edges to
             create a 3-D effect.
    F13      Press to segment the image by color.
    Meta-S   Press to swirl image pixels about the center.
    Meta-I   Press to implode image pixels about the center.
    Meta-W   Press to alter an image along a sine wave.
    Meta-P   Press to simulate an oil painting.
    Meta-C   Press to simulate a charcoal drawing.
    Alt-X    Press to composite the image
             with another.
    Alt-A    Press to annotate the image with text.
    Alt-D    Press to draw a line on the image.
    Alt-P    Press to edit an image pixel color.
    Alt-M    Press to edit the image matte information.
    Alt-X    Press to composite the image with another.
    Alt-A    Press to add a border to the image.
    Alt-F    Press to add a ornamental frame to the image.
    Alt-Shft-!   Press to add an image comment.
    Ctl-A    Press to apply image processing techniques to a
             region of interest.
    Shft-?   Press to display information about the image.
    Shft-+   Press to map the zoom image window.
    Shft-P   Press to preview an image enhancement, effect,
             or f/x.
    F1       Press to display helpful information about
             the "display" utility.
    Find     Press to browse documentation about
             GraphicsMagick.
    1-9      Press to change the level of magnification.
.fi

Use the arrow keys to move the image one pixel up, down, left, or right
within the magnify window. Be sure to first map the magnify window by pressing
button 2.

Press ALT and one of the arrow keys to trim off one pixel from any side
of the image.
.SH X RESOURCES

\fBDisplay\fP options can appear on the command line or in your X resource
file. Options on the command line supersede values specified in your X
resource file. See \fIX(1)\fP for more information on X resources.

Most \fBdisplay\fP options have a corresponding X resource. In addition,
\fBdisplay\fP
uses the following X resources:
.TP
.B "background \fI(class Background)"\fP
\fR
Specifies the preferred color to use for the Image window background. The
default is #ccc.
.TP
.B "borderColor \fI(class BorderColor)"\fP
\fR
Specifies the preferred color to use for the Image window border. The default
is #ccc.
.TP
.B "borderWidth \fI(class BorderWidth)"\fP
\fR
Specifies the width in pixels of the image window border. The default is
2.
.TP
.B "browseCommand \fI(class browseCommand)"\fP
\fR
Specifies the name of the preferred browser when displaying GraphicsMagick
documentation. The default is netscape %s.
.TP
.B "confirmExit \fI(class ConfirmExit)"\fP
\fR
\fBDisplay\fP pops up a dialog box to confirm exiting the program when
exiting the program. Set this resource to False to exit without
a confirmation.
.TP
.B "displayGamma \fI(class DisplayGamma)"\fP
\fR
Specifies the gamma of the X server.
\fR
You can apply separate gamma values to the red, green, and blue channels
of the image with a gamma value list delineated with slashes (i.e. 1.7/2.3/1.2).
\fR
The default is 2.2.
.TP
.B "displayWarnings \fI(class DisplayWarnings)"\fP
\fR
\fBDisplay\fP pops up a dialog box whenever a warning message occurs.
Set this resource to False to ignore warning messages.
.TP
.B "font \fI(class FontList)"\fP
\fR
Specifies the name of the preferred font to use in normal formatted text.
The default is 14 point Helvetica.
.TP
.B "font[1-9] \fI(class Font[1-9])"\fP
\fR
Specifies the name of the preferred font to use when
annotating
the image window with text. The default fonts are fixed, variable, 5x8,
6x10, 7x13bold, 8x13bold, 9x15bold, 10x20, and 12x24.
.TP
.B "foreground \fI(class Foreground)"\fP
\fR
Specifies the preferred color to use for text within the image window.
The default is black.
.TP
.B "gammaCorrect \fI(class gammaCorrect)"\fP
\fR
This resource, if true, will lighten or darken an image of known gamma
to match the gamma of the display (see resource \fBdisplayGamma\fP). The
default is True.
.TP
.B "geometry \fI(class Geometry)"\fP
\fR
Specifies the preferred size and position of the image window. It is not
necessarily obeyed by all window managers.

Offsets, if present, are handled in \fIX(1)\fP style.  A negative x offset is
measured from the right edge of the screen to the right edge of the icon,
and a negative y offset is measured from the bottom edge of the screen
to the bottom edge of the icon.
.TP
.B "iconGeometry \fI(class IconGeometry)"\fP
\fR
Specifies the preferred size and position of the application when iconified.
It is not necessarily obeyed by all window managers.

Offsets, if present, are handled in the same manner as in class Geometry.
.TP
.B "iconic \fI(class Iconic)"\fP
\fR
This resource indicates that you would prefer that the application's windows
initially not be visible as if the windows had be immediately iconified
by you. Window managers may choose not to honor the application's request.
.TP
.B "magnify \fI(class Magnify)"\fP
\fR
specifies an integral factor by which the image should be enlarged. The
default is 3.
\fR
This value only affects the magnification window which is invoked with
button
number 3 after the image is displayed.
.TP
.B "matteColor \fI(class MatteColor)"\fP
\fR
Specify the color of windows. It is used for the backgrounds of windows,
menus, and notices. A 3D effect is achieved by using highlight and shadow
colors derived from this color. Default value: #697B8F.
.TP
.B "name \fI(class Name)"\fP
\fR
This resource specifies the name under which resources for the application
should be found. This resource is useful in shell aliases to distinguish
between invocations of an application, without resorting to creating links
to alter the executable file name. The default is the application name.
.TP
.B "pen[1-9] \fI(class Pen[1-9])"\fP
\fR
Specifies the color of the preferred font to use when
annotating
the image window with text. The default colors are black, blue, green,
cyan, gray, red, magenta, yellow, and white.
.TP
.B "printCommand \fI(class PrintCommand)"\fP
\fR
This command is executed whenever Print is issued.  In general, it is the
command to print \fIPostScript\fP to your printer. Default value: lp
-c -s %i.
.TP
.B "sharedMemory \fI(class SharedMemory)"\fP
\fR
This resource specifies whether display should attempt use shared memory
for pixmaps. GraphicsMagick must be compiled with shared memory support,
and the display must support the MIT-SHM extension. Otherwise, this
resource is ignored. The default is True.
.TP
.B "textFont \fI(class textFont)"\fP
\fR
Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text. The default is 14 point Courier.
.TP
.B "title \fI(class Title)"\fP
\fR
This resource specifies the title to be used for the image window. This
information is sometimes used by a window manager to provide a header identifying
the window. The default is the image file name.
.TP
.B "undoCache \fI(class UndoCache)"\fP
\fR
Specifies, in mega-bytes, the amount of memory in the undo edit cache.
Each time you modify the image it is saved in the undo edit cache as long
as memory is available. You can subsequently \fIundo\fP one or more of
these transformations. The default is 16 Megabytes.
.TP
.B "usePixmap \fI(class UsePixmap)"\fP
\fR
Images are maintained as a XImage by default. Set this resource to True
to utilize a server Pixmap instead. This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image. Panning is much faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with discretion.

To set the geometry of the Magnify or Pan or window, use the geometry resource.
For example, to set the Pan window geometry to 256x256, use:

.nf
    gm display.pan.geometry: 256x256
.fi
.SH IMAGE LOADING

To select an image to display, choose \fBOpen\fP of the \fBFile\fP sub-menu
from the Command widget. A file browser is displayed.
To choose a particular image file, move the pointer to the filename and
press any button. The filename is copied to the text window. Next, press
\fBOpen\fP
or press the \fBRETURN\fP key. Alternatively, you can type the image file
name directly into the text window. To descend directories, choose a directory
name and press the button twice quickly. A scrollbar allows a large list
of filenames to be moved through the viewing area if it exceeds the size
of the list area.

You can trim the list of file names by using shell globbing characters.
For example, type *.jpg to list only files that end
with .jpg.

To select your image from the X server screen instead of from a file, Choose
\fBGrab\fP of the \fBOpen\fP widget.
.SH VISUAL IMAGE DIRECTORY

To create a Visual Image Directory, choose Visual Directory of the \fBFile\fP
sub-menu from the Command widget . A file browser is
displayed. To create a Visual Image Directory from all the images in the
current directory, press \fBDirectory\fP or press the \fBRETURN key\fP.
Alternatively, you can select a set of image names by using shell globbing
characters. For example, type *.jpg to include only files that
end with .jpg. To descend directories, choose a directory name
and press the button twice quickly. A scrollbar allows a large list of
filenames to be moved through the viewing area if it exceeds the size of
the list area.

After you select a set of files, they are turned into thumbnails and tiled
onto a single image. Now move the pointer to a particular thumbnail and
press \fBbutton 3\fP and drag. Finally, select Open. The image represented
by the thumbnail is displayed at its full size. Choose \fBNext\fP from
the \fBFile\fP sub-menu of the Command widget to return to the Visual
Image Directory.
.SH IMAGE CUTTING

Note that cut information for image window is not retained for colormapped
X server visuals (e.g. \fIStaticColor\fP,
\fIStaticColor\fP, \fIGRAYScale\fP,
\fIPseudoColor\fP).
Correct cutting behavior may require a \fITrueColor\fP or \fIDirectColor\fP
visual or a \fIStandard Colormap\fP.

To begin, press choose \fBCut\fP of the \fBEdit\fP sub-menu from the
Command
widget. Alternatively, press
\fBF3\fP in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in cut mode. In cut mode, the Command widget has these
options:

    \fBHelp\fP
    \fBDismiss\fP


To define a cut region, press button 1 and drag. The cut region is defined
by a highlighted rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the cut region, release the button.
You are now in rectify mode. In rectify mode, the Command widget has these
options:

    \fBCut\fP
    \fBHelp\fP
    \fBDismiss\fP


You can make adjustments by moving the pointer to one of the cut rectangle
corners, pressing a button, and dragging. Finally, press Cut to commit
your copy region. To exit without cutting the image, press Dismiss.
.SH IMAGE COPYING

To begin, press choose \fBCopy\fP of the \fBEdit\fP sub-menu from the
Command
widget. Alternatively, press
\fBF4\fP in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in copy mode. In copy mode, the Command widget has
these options:

    Help
    Dismiss


To define a copy region, press button 1 and drag. The copy region is defined
by a highlighted rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the copy region, release the button.
You are now in rectify mode. In rectify mode, the Command widget has these
options:

    Copy
    Help
    Dismiss


You can make adjustments by moving the pointer to one of the copy rectangle
corners, pressing a button, and dragging. Finally, press Copy to commit
your copy region. To exit without copying the image, press Dismiss.
.SH IMAGE PASTING

To begin, press choose \fBPaste\fP of the \fBEdit\fP sub-menu from the
Command
widget. Alternatively, press
\fBF5\fP in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in Paste mode. To exit immediately, press Dismiss.
In Paste mode, the Command widget has these options:

    \fBOperators\fP

    over
    in
    out
    atop
    xor
    plus
    minus
    add
    subtract
    difference
    multiply
    bumpmap
    replace

    \fBHelp\fP
    \fBDismiss\fP


Choose a composite operation from the \fBOperators\fP sub-menu of the
Command
widget. How each operator behaves is described below. \fIimage window\fP
is the image currently displayed on your X server and \fIimage\fP is the
image obtained with the File Browser widget.
.TP
.B "over"
\fR
The result is the union of the two image shapes, with \fIimage\fP obscuring
\fIimage
window\fP in the region of overlap.
.TP
.B "in"
\fR
The result is simply \fIimage\fP cut by the shape of
\fIimage window\fP.
None of the image data of image window is in the result.
.TP
.B "out"
\fR
The resulting image is \fIimage\fP with the shape of
\fIimage window\fP
cut out.
.TP
.B "atop"
\fR
The result is the same shape as \fIimage window\fP, with
\fIimage\fP
obscuring \fIimage window\fP where the image shapes overlap. Note this
differs from over because the portion of image outside
\fIimage window\fP's
shape does not appear in the result.
.TP
.B "xor"
\fR
The result is the image data from both \fIimage\fP and
\fIimage window\fP
that is outside the overlap region. The overlap region is blank.
.TP
.B "plus"
\fR
The result is just the sum of the image data. Output values are cropped
to the maximum value (no overflow). This operation is independent of the
matte channels.
.TP
.B "minus"
\fR
The result of \fIimage\fP - \fIimage window\fP, with underflow cropped
to zero. The matte channel is ignored (set to opaque, full coverage).
.TP
.B "add"
\fR
The result of \fIimage\fP + \fIimage window\fP, with overflow wrapping
around (mod MaxRGB+1).
.TP
.B "subtract"
\fR
The result of \fIimage\fP - \fIimage window\fP, with underflow wrapping
around (mod MaxRGB+1). The add and subtract operators can be used to perform
reversible transformations.
.TP
.B "difference"
\fR
The result of abs(\fIimage\fP - \fIimage window\fP). This is useful for
comparing two very similar images.
.TP
.B "multiply"
\fR
The result of \fIimage\fP * \fIimage window\fP. This is useful for
the creation of drop-shadows.
.TP
.B "bumpmap"
\fR
The result of \fIimage window\fP shaded by \fIwindow\fP.
.TP
.B "replace"
\fRThe resulting image is \fIimage window\fP replaced with
\fIimage\fP.
Here the matte information is ignored.

The image compositor requires a matte, or alpha channel in the image for
some operations. This extra channel usually defines a mask which represents
a sort of a cookie-cutter for the image. This is the case when matte is
255 (full coverage) for pixels inside the shape, zero outside, and between
zero and 255 on the boundary. If image does not have a matte channel, it
is initialized with 0 for any pixel matching in color to pixel location
(0,0), otherwise 255. See Matte Editing for a method
of defining a matte channel.

Note that matte information for image window is not retained for colormapped
X server visuals (e.g. \fIStaticColor, StaticColor, GrayScale, PseudoColor\fP).
Correct compositing behavior may require a
\fITrueColor\fP or \fIDirectColor\fP
visual or a \fIStandard Colormap\fP.

Choosing a composite operator is optional. The default operator is replace.
However, you must choose a location to composite your image and press button
1. Press and hold the button before releasing and an outline of the image
will appear to help you identify your location.

The actual colors of the pasted image is saved. However, the color that
appears in image window may be different. For example, on a monochrome
screen image window will appear black or white even though your pasted
image may have many colors. If the image is saved to a file it is written
with the correct colors. To assure the correct colors are saved in the
final image, any \fIPseudoClass\fP image is promoted to \fIDirectClass\fP.
To force a
\fIPseudoClass\fP image to remain \fIPseudoClass\fP,
use \fB-colors\fP.
.SH IMAGE CROPPING

To begin, press choose \fBCrop\fP of the \fBTransform\fP submenu from
the Command widget. Alternatively,
press C in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in crop mode. In crop mode, the Command widget has
these options:

    \fBHelp\fP
    \fBDismiss\fP


To define a cropping region, press button 1 and drag. The cropping region
is defined by a highlighted rectangle that expands or contracts as it follows
the pointer. Once you are satisfied with the cropping region, release the
button. You are now in rectify mode. In rectify mode, the Command widget
has these options:

    \fBCrop\fP
    \fBHelp\fP
    \fBDismiss\fP


You can make adjustments by moving the pointer to one of the cropping rectangle
corners, pressing a button, and dragging. Finally, press Crop to commit
your cropping region. To exit without cropping the image, press Dismiss.
.SH IMAGE CHOPPING

An image is chopped interactively. There is no command line argument to
chop an image. To begin, choose \fBChop\fP of the \fBTransform\fP sub-menu
from the Command widget. Alternatively,
press [ in the Image window.

You are now in \fBChop\fP mode. To exit immediately, press
\fBDismiss\fP.
In Chop mode, the Command widget has these options:

    \fBDirection\fP

    horizontal
    vertical

    \fBHelp\fP
    \fBDismiss\fP


If the you choose the horizontal direction (this is the default), the area
of the image between the two horizontal endpoints of the chop line is removed.
Otherwise, the area of the image between the two vertical endpoints of
the chop line is removed.

Select a location within the image window to begin your chop, press and
hold any button. Next, move the pointer to another location in the image.
As you move a line will connect the initial location and the pointer. When
you release the button, the area within the image to chop is determined
by which direction you choose from the Command widget.

To cancel the image chopping, move the pointer back to the starting point
of the line and release the button.
.SH IMAGE ROTATION

Press the / key to rotate the image 90 degrees or \\ to rotate -90 degrees.
To interactively choose the degree of rotation, choose
\fBRotate...\fP
of the \fBTransform\fP submenu from the Command Widget.
Alternatively, press * in the image window.

A small horizontal line is drawn next to the pointer. You are now in rotate
mode. To exit immediately, press Dismiss. In rotate mode, the Command widget
has these options:

    \fBPixel Color\fP

    black
    blue
    cyan
    green
    gray
    red
    magenta
    yellow
    white
    Browser...

    \fBDirection\fP

    horizontal
    vertical

    \fBHelp\fP
    \fBDismiss\fP


Choose a background color from the Pixel Color sub-menu. Additional background
colors can be specified with the color browser. You can change the menu
colors by setting the X resources pen1 through pen9.

If you choose the color browser and press \fBGrab\fP, you can select the
background color by moving the pointer to the desired color on the screen
and press any button.

Choose a point in the image window and press this button and hold. Next,
move the pointer to another location in the image. As you move a line connects
the initial location and the pointer. When you release the button, the
degree of image rotation is determined by the slope of the line you just
drew. The slope is relative to the direction you choose from the Direction
sub-menu of the Command widget.

To cancel the image rotation, move the pointer back to the starting point
of the line and release the button.
.SH IMAGE ANNOTATION

An image is annotated interactively. There is no command line argument
to annotate an image. To begin, choose
\fBAnnotate\fP of the \fBImage
Edit\fP sub-menu from the Command widget. Alternatively,
press a in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in annotate mode. To exit immediately, press Dismiss.
In annotate mode, the Command widget has these options:

    
\fBFont Name\fP

    
fixed
    
variable
    
5x8
    
6x10
    
7x13bold
    
8x13bold
    
9x15bold
    
10x20
    
12x24
    
Browser...

    
\fBFont Color\fP

    
black
    
blue
    
cyan
    
green
    
gray
    
red
    
magenta
    
yellow
    
white
    
transparent
    
Browser...

    
\fBBox Color\fP

    
black
    
blue
    
cyan
    
green
    
gray
    
red
    
magenta
    
yellow
    
white
    
transparent
    
Browser...

    
\fBRotate Text\fP

    
-90
    
-45
    
-30
    
0
    
30
    
45
    
90
    
180
    
Dialog...

    
\fBHelp\fP
    
\fBDismiss\fP


Choose a font name from the \fBFont Name\fP sub-menu. Additional font
names can be specified with the font browser. You can change the menu names
by setting the X resources font1 through font9.

Choose a font color from the \fBFont Color\fP sub-menu. Additional font
colors can be specified with the color browser. You can change the menu
colors by setting the X resources pen1 through pen9.

If you select the color browser and press \fBGrab\fP, you can choose the
font color by moving the pointer to the desired color on the screen and
press any button.

If you choose to rotate the text, choose \fBRotate Text\fP from the menu
and select an angle. Typically you will only want to rotate one line of
text at a time. Depending on the angle you choose, subsequent lines may
end up overwriting each other.

Choosing a font and its color is optional. The default font is fixed and
the default color is black. However, you must choose a location to begin
entering text and press a button. An underscore character will appear at
the location of the pointer. The cursor changes to a pencil to indicate
you are in text mode. To exit immediately, press Dismiss.

In text mode, any key presses will display the character at the location
of the underscore and advance the underscore cursor. Enter your text and
once completed press Apply to finish your image annotation. To correct
errors press \fBBACK SPACE\fP. To delete an entire line of text, press
\fBDELETE\fP.
Any text that exceeds the boundaries of the image window is automatically
continued onto the next line.

The actual color you request for the font is saved in the image. However,
the color that appears in your Image window may be different. For example,
on a monochrome screen the text will appear black or white even if you
choose the color red as the font color. However, the image saved to a file
with \fB-write\fP is written with red lettering. To assure the correct
color text in the final image, any \fIPseudoClass\fP image is promoted
to \fIDirectClass\fP (see miff(5)). To force a \fIPseudoClass\fP image
to remain
\fIPseudoClass\fP, use \fB-colors\fP.
.SH IMAGE COMPOSITING

An image composite is created interactively. \fBThere is no command line
argument to composite an image\fP. To begin, choose \fBComposite\fP of
the \fBImage Edit\fP from the Command widget. Alternatively,
press x in the Image window.

First a popup window is displayed requesting you to enter an image name.
Press \fBComposite\fP, \fBGrab\fP or type a file name. Press \fBCancel\fP
if you choose not to create a composite image. When you choose \fBGrab\fP,
move the pointer to the desired window and press any button.

If the \fBComposite\fP image does not have any matte information, you
are informed and the file browser is displayed again. Enter the name of
a mask image. The image is typically grayscale and the same size as the
composite image. If the image is not grayscale, it is converted to grayscale
and the resulting intensities are used as matte information.

A small window appears showing the location of the cursor in the image
window. You are now in composite mode. To exit immediately, press Dismiss.
In composite mode, the Command widget has these options:

    
\fBOperators\fP

    
over
    
in
    
out
    
atop
    
xor
    
plus
    
minus
    
add
    
subtract
    
difference
    
bumpmap
    
replace

    
\fBBlend\fP
    
\fBDisplace\fP
    
\fBHelp\fP
    
\fBDismiss\fP


Choose a composite operation from the Operators sub-menu of the Command
widget. How each operator behaves is described below. image window is the
image currently displayed on your X server and image is the image obtained
.TP
.B "over"
\fR
The result is the union of the two image shapes, with \fIimage\fP obscuring
\fIimage
window\fP in the region of overlap.
.TP
.B "in"
\fR
The result is simply \fIimage\fP cut by the shape of
\fIimage window\fP.
None of the image data of image window is in the result.
.TP
.B "out"
\fR
The resulting image is \fIimage\fP with the shape of
\fIimage window\fP
cut out.
.TP
.B "atop"
\fR
The result is the same shape as \fIimage window\fP, with
\fIimage\fP
obscuring \fIimage window\fP where the image shapes overlap. Note this
differs from over because the portion of image outside
\fIimage window\fP's
shape does not appear in the result.
.TP
.B "xor"
\fR
The result is the image data from both \fIimage\fP and
\fIimage window\fP
that is outside the overlap region. The overlap region is blank.
.TP
.B "plus"
\fR
The result is just the sum of the image data. Output values are cropped
to 255 (no overflow). This operation is independent of the matte channels.
.TP
.B "minus"
\fR
The result of \fIimage\fP - \fIimage window\fP, with underflow cropped
to zero. The matte channel is ignored (set to 255, full coverage).
.TP
.B "add"
\fR
The result of \fIimage\fP + \fIimage window\fP, with overflow wrapping
around (mod 256).
.TP
.B "subtract"
\fR
The result of \fIimage\fP - \fIimage window\fP, with underflow wrapping
around (mod 256). The add and subtract operators can be used to perform
reversible transformations.
.TP
.B "difference"
\fR
The result of abs(\fIimage\fP - \fIimage window\fP). This is useful for
comparing two very similar images.
.TP
.B "bumpmap"
\fR
The result of \fIimage window\fP shaded by \fIwindow\fP.
.TP
.B "replace"
\fR
The resulting image is \fIimage window\fP replaced with
\fIimage\fP.
Here the matte information is ignored.

The image compositor requires a matte, or alpha channel in the image for
some operations. This extra channel usually defines a mask which represents
a sort of a cookie-cutter for the image. This is the case when matte is
255 (full coverage) for pixels inside the shape, zero outside, and between
zero and 255 on the boundary. If image does not have a matte channel, it
is initialized with 0 for any pixel matching in color to pixel location
(0,0), otherwise 255. See Matte Editing for a method
of defining a matte channel.

If you choose \fBblend\fP, the composite operator becomes \fBover\fP.
The image matte channel percent transparency is initialized to factor.
The image window is initialized to (100-factor). Where factor is the value
you specify in the Dialog widget.

\fBDisplace\fP shifts the image pixels as defined by a displacement map.
With this option, \fIimage\fP is used as a displacement map. Black, within
the displacement map, is a maximum positive displacement. White is a maximum
negative displacement and middle gray is neutral. The displacement is scaled
to determine the pixel shift. By default, the displacement applies in both
the horizontal and vertical directions. However, if you specify
\fImask\fP,
\fIimage\fP
is the horizontal X displacement and
\fImask\fP the vertical Y displacement.

Note that matte information for image window is not retained for colormapped
X server visuals (e.g.
\fIStaticColor, StaticColor, GrayScale, PseudoColor\fP).
Correct compositing behavior may require a \fITrueColor\fP or
\fIDirectColor\fP
visual or a \fIStandard Colormap\fP.

Choosing a composite operator is optional. The default operator is replace.
However, you must choose a location to composite your image and press button
1. Press and hold the button before releasing and an outline of the image
will appear to help you identify your location.

The actual colors of the composite image is saved. However, the color that
appears in image window may be different. For example, on a monochrome
screen Image window will appear black or white even though your composited
image may have many colors. If the image is saved to a file it is written
with the correct colors. To assure the correct colors are saved in the
final image, any PseudoClass image is promoted to \fIDirectClass\fP (see
miff).
To force a \fIPseudoClass\fP image to remain \fIPseudoClass\fP,
use \fB-colors\fP.
.SH COLOR EDITING

Changing the the color of a set of pixels is performed interactively. There
is no command line argument to edit a pixel. To begin, choose \fBColor\fP
from the \fBImage Edit\fP submenu of the Command widget.
Alternatively, press c in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in color edit mode. To exit immediately, press \fBDismiss\fP.
In color edit mode, the
\fBCommand widget\fP has these options:

    
\fBMethod\fP

    
point
    
replace
    
floodfill
    
reset

    
\fBPixel Color\fP

    
black
    
blue
    
cyan
    
green
    
gray
    
red
    
magenta
    
yellow
    
white
    
Browser...

    
\fBBorder Color\fP

    
black
    
blue
    
cyan
    
green
    
gray
    
red
    
magenta
    
yellow
    
white
    
Browser...

    
\fBFuzz\fP

    
0
    
2
    
4
    
8
    
16
    Dialog...

    
\fBUndo\fP
    
\fBHelp\fP
    
\fBDismiss\fP


Choose a color editing method from the \fBMethod\fP sub-menu of
the Command
widget. The \fBpoint method\fP recolors any pixel selected with the
pointer unless the button is released. The \fBreplace method\fP recolors
any pixel that matches the color of the pixel you select with a button
press. \fBFloodfill\fP recolors any pixel that matches the color of the
pixel you select with a button press and is a neighbor.
Whereas \fBfilltoborder\fP
changes the matte value of any neighbor pixel that is not the border color.
Finally \fBreset\fP changes the entire image to the designated color.

Next, choose a pixel color from the \fBPixel Color\fP sub-menu. Additional
pixel colors can be specified with the color browser. You can change the
menu colors by setting the X resources pen1 through
pen9.

Now press button 1 to select a pixel within the Image window to change
its color. Additional pixels may be recolored as prescribed by the method
you choose. additional pixels by increasing the Delta value.

If the \fBMagnify widget\fP is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2). Alternatively you can
select a pixel to recolor from within the \fBMagnify widget\fP. Move the
pointer to the \fBMagnify widget\fP and position the pixel with the cursor
control keys. Finally, press a button to recolor the selected pixel (or
pixels).

The actual color you request for the pixels is saved in the image. However,
the color that appears in your Image window may be different. For example,
on a monochrome screen the pixel will appear black or white even if you
choose the color red as the pixel color. However, the image saved to a
file with -write is written with red pixels. To assure the correct color
text in the final image, any \fIPseudoClass\fP image is promoted
to \fIDirectClass\fP
To force a \fIPseudoClass\fP image to remain
\fIPseudoClass\fP, use \fB-colors\fP.
.SH MATTE EDITING

Matte information within an image is useful for some operations such as
image compositing. This extra channel usually defines
a mask which represents a sort of a cookie-cutter for the image. This is
the case when matte is 255 (full coverage) for pixels inside the shape,
zero outside, and between zero and 255 on the boundary.

Setting the matte information in an image is done interactively. There
is no command line argument to edit a pixel. To begin, and choose \fBMatte\fP
of the \fBImage Edit\fP sub-menu from the Command widget.

Alternatively, press m in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in matte edit mode. To exit immediately, press Dismiss.
In matte edit mode, the Command widget has these options:

    
\fBMethod\fP

    
point
    
replace
    
floodfill
    
reset

    
\fBBorder Color\fP

    
black
    
blue
    
cyan
    
green
    
gray
    
red
    
magenta
    
yellow
    
white
    
Browser...

    
\fBFuzz\fP

    
0
    
2
    
4
    
8
    
16
    Dialog...

    
\fBMatte\fP
    
\fBUndo\fP
    
\fBHelp\fP
    
\fBDismiss\fP

Choose a matte editing method from the \fBMethod\fP sub-menu of the Command
widget. The \fBpoint method\fP changes the matte value of the any
pixel selected with the pointer until the button is released. The \fBreplace
method\fP changes the matte value of any pixel that matches the color
of the pixel you select with a button press. \fBFloodfill\fP changes the
matte value of any pixel that matches the color of the pixel you select
with a button press and is a neighbor. Whereas
\fBfilltoborder\fP recolors
any neighbor pixel that is not the border color. Finally \fBreset\fP changes
the entire image to the designated matte value.
Choose \fBMatte Value\fP and a dialog appears requesting a matte value.
Enter a value between \fB0 and 255\fP. This value is assigned as the matte
value of the selected pixel or pixels.
Now, press any button to select a pixel within the Image window to change
its matte value. You can change the matte value of additional pixels by
increasing the Delta value. The Delta value is first added then subtracted
from the red, green, and blue of the target color. Any pixels within the
range also have their matte value updated.
If the \fBMagnify widget\fP is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2). Alternatively you can
select a pixel to change the matte value from within the
\fBMagnify widget\fP.
Move the pointer to the \fBMagnify widget\fP and position the pixel with
the cursor control keys. Finally, press a button to change the matte value
of the selected pixel (or pixels).
Matte information is only valid in a \fIDirectClass image\fP. Therefore,
any \fIPseudoClass\fP image is promoted to
\fIDirectClass\fP. Note that
matte information for \fIPseudoClass\fP is not retained for colormapped
X server visuals (e.g. \fIStaticColor, StaticColor, GrayScale, PseudoColor\fP)
unless you immediately save your image to a file (refer to Write). Correct
matte editing behavior may require a \fITrueColor\fP or \fIDirectColor\fP
visual or a \fIStandard Colormap\fP.
.SH IMAGE DRAWING

An image is drawn upon interactively. \fBThere is no command line argument
to draw on an image\fP. To begin, choose \fBDraw\fP of the Image \fBEdit\fP
sub-menu from the Command widget.
Alternatively, press d in the image window.

The cursor changes to a crosshair to indicate you are in draw mode. To
exit immediately, press Dismiss. In draw mode, the Command widget has these
options:

    
\fBPrimitive\fP

    
point
    
line
    
rectangle
    
fill rectangle
    
circle
    
fill circle
    
ellipse
    
fill ellipse
    
polygon
    
fill polygon

    
\fBColor\fP

    
black
    
blue
    
cyan
    
green
    
gray
    
red
    
magenta
    
yellow
    
white
    
transparent
    
Browser...

    
\fBStipple\fP

    
Brick
    
Diagonal
    
Scales
    
Vertical
    
Wavy
    
Translucent
    
Opaque
    
Open...

    
\fBWidth\fP

    
1
    
2
    
4
    
8
    
16
    Dialog...

    
\fBUndo\fP
    
\fBHelp\fP
    
\fBDismiss\fP

Choose a drawing primitive from the \fBPrimitive\fP sub-menu.

Next, choose a color from the \fBColor\fP sub-menu. Additional colors
can be specified with the color browser. You can change the menu colors
by setting the X resources pen1 through pen9. The transparent
color updates the image matte channel and is useful for image compositing.

If you choose the color browser and press \fBGrab\fP, you can select the
primitive color by moving the pointer to the desired color on the screen
and press any button. The transparent color updates the image matte channel
and is useful for image compositing.

Choose a stipple, if appropriate, from the \fBStipple\fP sub-menu. Additional
stipples can be specified with the file browser. Stipples obtained from
the file browser must be on disk in the X11 bitmap format.

Choose a line width, if appropriate, from the \fBWidth\fP sub-menu. To
choose a specific width select the \fBDialog\fP widget.

Choose a point in the image window and press button 1 and hold. Next, move
the pointer to another location in the image. As you move, a line connects
the initial location and the pointer. When you release the button, the
image is updated with the primitive you just drew. For polygons, the image
is updated when you press and release the button without moving the pointer.

To cancel image drawing, move the pointer back to the starting point of
the line and release the button.
.SH REGION OF INTEREST

To begin, press choose Region of Interest of the Pixel Transform sub-menu
from the Command widget.
Alternatively, press R in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in region of interest mode. In region of interest mode,
the Command widget has these options:

    
\fBHelp\fP
    
\fBDismiss\fP


To define a region of interest, press button 1 and drag. The region of
interest is defined by a highlighted rectangle that expands or contracts
as it follows the pointer. Once you are satisfied with the region of interest,
release the button. You are now in apply mode. In apply mode the Command
widget has these options:

    
\fBFile\fP

    
Save...
    
Print...

    
\fBEdit\fP

    
Undo
    
Redo

    
\fBTransform\fP

    
Flip
    
Flop
    
Rotate Right
    
Rotate Left

    
\fBEnhance\fP

    
Hue...
    
Saturation...
    
Brightness...
    
Gamma...
    
Spiff
    
Dull
    
Equalize
    
Normalize
    
Negate
    
GRAYscale
    
Quantize...

    
\fBEffects\fP

    
Despeckle
    
Emboss
    
Reduce Noise
    
Add Noise
    
Sharpen...
    
Blur...
    
Threshold...
    
Edge Detect...
    
Spread...
    
Shade...
    
Raise...
    
Segment...



    
\fBF/X\fP

    
Solarize...
    
Swirl...
    
Implode...
    
Wave...
    
Oil Paint
    
Charcoal Draw...



    
\fBMiscellany\fP

    
Image Info
    
Zoom Image
    
Show Preview...
    
Show Histogram
    
Show Matte

    
\fBHelp\fP
    
\fBDismiss\fP


You can make adjustments to the region of interest by moving the pointer
to one of the rectangle corners, pressing a button, and dragging. Finally,
choose an image processing technique from the Command widget. You can choose
more than one image processing technique to apply to an area. Alternatively,
you can move the region of interest before applying another image processing
technique. To exit, press Dismiss.
.SH IMAGE PANNING

When an image exceeds the width or height of the X server screen, display
maps a small panning icon. The rectangle within the panning icon shows
the area that is currently displayed in the the image window. To pan about
the image, press any button and drag the pointer within the panning icon.
The pan rectangle moves with the pointer and the image window is updated
to reflect the location of the rectangle within the panning icon. When
you have selected the area of the image you wish to view, release the button.

Use the arrow keys to pan the image one pixel up, down, left, or right
within the image window.

The panning icon is withdrawn if the image becomes smaller than the dimensions
of the X server screen.
.SH USER PREFERENCES

Preferences affect the default behavior of \fBdisplay(1)\fP. The preferences
are either true or false and are stored in your home directory
as .displayrc:
.in 15

.in 15
.B "
\fBdisplay image centered on a backdrop\fP"
.in 20
 \fR
.in 20

This backdrop covers the entire workstation screen and is useful for hiding
other X window activity while viewing the image. The color of the backdrop
is specified as the background color. Refer to X Resources
for details.
.in 15
.in 15
.B "
\fBconfirm on program exit\fP"
.in 20
 \fR
.in 20

Ask for a confirmation before exiting the \fBdisplay(1)\fP program.
.in 15
.in 15
.B "
\fBcorrect image for display gamma\fP"
.in 20
 \fR
.in 20

If the image has a known gamma, the gamma is corrected to match that of
the X server (see the X Resource\fB displayGamma\fP).
.in 15
.in 15
.B "
\fBdisplay warning messages\fP"
.in 20
 \fR
.in 20

Display any warning messages.
.in 15
.in 15
.B "
\fBapply Floyd/Steinberg error diffusion to image\fP"
.in 20
 \fR
.in 20

The basic strategy of dithering is to trade intensity resolution for spatial
resolution by averaging the intensities of several neighboring pixels.
Images which suffer from severe contouring when reducing colors can be
improved with this preference.
.in 15
.in 15
.B "
\fBuse a shared colormap for colormapped X visuals\fP"
.in 20
 \fR
.in 20

This option only applies when the default X server visual is
\fIPseudoColor\fP
or \fIGRAYScale\fP. Refer to \fB-visual\fP for more details. By default,
a shared colormap is allocated. The image shares colors with other X clients.
Some image colors could be approximated, therefore your image may look
very different than intended. Otherwise the image colors appear exactly
as they are defined. However, other clients may go technicolor when the
image colormap is installed.
.in 15
.in 15
.B "
\fBdisplay images as an X server pixmap\fP"
.in 20
 \fR
.in 20

Images are maintained as a XImage by default. Set this resource to True
to utilize a server Pixmap instead. This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image. Panning is much faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with discretion.
.in 15

.TP
.in 15
.in 15
.in 20
.SH GM IDENTIFY

\fBIdentify\fP describes the format and characteristics of one or
more image files as internally supported by the software. It will also
report if an image is incomplete or corrupt.  The information
displayed includes the scene number, the file name, the width and
height of the image, whether the image is colormapped or not, the
number of colors in the image, the number of bytes in the image, the
format of the image (JPEG, PNM, etc.), and finally the number of
seconds in both user time and elapsed time it took to read and process
the image.  If -verbose or +ping are provided as an option, the pixel
read rate is also displayed. An example line output from
\fBidentify\fP follows:

.nf
    images/aquarium.miff 640x480 PseudoClass 256c
           308135b MIFF 0.000u 0:01
.fi

If -verbose is set, expect additional output including any image
comment:


.nf
    Image: images/aquarium.miff
    class: PseudoClass
    colors: 256
    signature: eb5dca81dd93ae7e6ffae99a527eb5dca8...
    matte: False
    geometry: 640x480
       depth: 8
    bytes: 308135
    format: MIFF
    comments:
    Imported from MTV raster image: aquarium.mtv
.fi

For some formats, additional format-specific information about the file
will be written if the -debug coder or -debug all option
is used.
.SH IDENTIFY OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images immediately
following, until the set is terminated by the appearance of any option
or \fB-noop\fP.

For a more detailed description of each option, see
Options, above.

.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-format \fI<string>"\fP
\fRoutput formatted image characteristics
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-ping"
\fRefficiently determine image characteristics
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string

For a more detailed description of each option, see
Options, above.

.SH GM IMPORT

\fBImport\fP reads an image from any visible window on an X server and
outputs it as an image file. You can capture a single window, the entire
screen, or any rectangular portion of the screen.
Use \fIdisplay\fP
for redisplay, printing, editing, formatting, archiving, image processing,
etc. of the captured image.

The target window can be specified by id, name, or may be selected
by clicking the mouse in the desired window. If you press a button and
then drag, a rectangle will form which expands and contracts as the mouse
moves. To save the portion of the screen defined by the rectangle, just
release the button. The keyboard bell is rung once at the beginning of
the screen capture and twice when it completes.
.SH EXAMPLES

To select an X window or an area of the screen with the mouse and save it
in the MIFF image format to a file entitled window.miff, use:

.nf
    gm import window.miff
.fi

To select an X window or an area of the screen with the mouse and save it
in the Encapsulated PostScript format to include in another document, use:

.nf
    gm import figure.eps
.fi

To capture the entire X server screen in the JPEG image format in a file
entitled root.jpeg, without using the mouse, use:

.nf
    gm import -window root root.jpeg
.fi

To capture the 512x256 area at the upper right corner of the X server
screen in the PNG image format in a well-compressed file entitled corner.png,
without using the mouse,  use:

.nf
    gm import -window root -crop 512x256-0+0 -quality 90
           corner.png
.fi
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect until it is explicitly changed by specifying
the option again with a different effect.

\fBImport\fP options can appear on the command line or in your
X resources file. See \fIX(1)\fP. Options on the command line supersede
values specified in your X resources file.

For a more detailed description of each option, see
Options, above.

.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-delay \fI<1/100ths of a second>"\fP
\fRdisplay the next image after pausing
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-descend"
\fRobtain image by descending window hierarchy
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-encoding \fI<type>"\fP
\fRspecify the text encoding
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-frame"
\fRinclude the X window frame in the imported image
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-negate"
\fRreplace every pixel with its complementary color
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas
.TP
.B "-pause \fI<seconds>"\fP
\fRpause between snapshots [import]
.TP
.B "-ping"
\fRefficiently determine image characteristics
.TP
.B "-pointsize \fI<value>"\fP
\fRpointsize of the PostScript, X11, or TrueType font
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
.TP
.B "-resize \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scene \fI<value>"\fP
\fRset scene number
.TP
.B "-screen"
\fRspecify the screen to capture
.TP
.B "-set \fI<attribute> <value>"\fP
\fRset an image attribute
.TP
.B "+set \fI<attribute>"\fP
\fRunset an image attribute
.TP
.B "-silent"
\fRoperate silently
.TP
.B "-snaps \fI<value>"\fP
\fRnumber of screen snapshots
.TP
.B "-thumbnail \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image (quickly)
.TP
.B "-transparent \fI<color>"\fP
\fRmake this color transparent within the image
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string

For a more detailed description of each option, see
Options, above.

.SH GM MOGRIFY

\fBMogrify\fP transforms an image or a sequence of images. These transforms
include image scaling, image rotation, color reduction, and others. Each
transmogrified image overwrites the corresponding original image, unless an
option such as
\fB-format\fP causes the output filename to be different from the input
filename.

The graphics formats supported by \fBmogrify\fP are listed in
\fIGraphicsMagick(1)\fP.
.SH EXAMPLES

To convert all the TIFF files in a particular directory to JPEG, use:

.nf
    gm mogrify -format jpeg *.tiff
.fi

To convert a directory full of JPEG images to thumbnails, use:

.nf
    gm mogrify -size 120x120 *.jpg -resize 120x120 +profile "*"
.fi

In this example, '-size 120x120' gives a hint to the JPEG decoder
that the images are going to be downscaled to 120x120, allowing it to run
faster by avoiding returning full-resolution images to GraphicsMagick for
the subsequent resizing operation.  The
\'-resize 120x120' specifies the desired dimensions of the
output images.  It will be scaled so its largest dimension is 120 pixels.  The
\'+profile "*"' removes any ICM, EXIF, IPTC, or other profiles
that might be present in the input and aren't needed in the thumbnails.

To scale an image of a cockatoo to exactly 640 pixels in width and 480
pixels in height, use: 

.nf
    gm mogrify -resize 640x480! cockatoo.miff
.fi
.SH OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images that follows,
until the set is terminated by the appearance of any option or \fB-noop\fP.

For a more detailed description of each option, see
Options, above.

.TP
.B "-affine \fI<matrix>"\fP
\fRdrawing transform matrix
.TP
.B "-antialias"
\fRremove pixel aliasing
.TP
.B "-asc-cdl \fI<spec>"\fP
\fRapply ASC CDL color transform
.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-auto-orient"
\fRorient (rotate) image so it is upright
.TP
.B "-background \fI<color>"\fP
\fRthe background color
.TP
.B "-black-threshold \fIred[,green][,blue][,opacity]"\fP
\fRpixels below the threshold become black
.TP
.B "-blue-primary \fI<x>,<y>"\fP
\fRblue chromaticity primary point
.TP
.B "-blur \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator
.TP
.B "-border \fI<width>x<height>"\fP
\fRsurround the image with a border of color
.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color
.TP
.B "-channel \fI<type>"\fP
\fRthe type of channel
.TP
.B "-charcoal \fI<factor>"\fP
\fRsimulate a charcoal drawing
.TP
.B "-colorize \fI<value>"\fP
\fRcolorize the image with the pen color
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment
.TP
.B "-compose \fI<operator>"\fP
\fRthe type of image composition
.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression
.TP
.B "-contrast"
\fRenhance or reduce the image contrast
.TP
.B "-convolve \fI<kernel>"\fP
\fRconvolve image with the specified convolution kernel
.TP
.B "-create-directories"
\fRcreate output directory if required
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image
.TP
.B "-cycle \fI<amount>"\fP
\fRdisplace image colormap by amount
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-delay \fI<1/100ths of a second>"\fP
\fRdisplay the next image after pausing
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-despeckle"
\fRreduce the speckles within an image
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-draw \fI<string>"\fP
\fRannotate an image with one or more graphic primitives
.TP
.B "-edge \fI<radius>"\fP
\fRdetect edges within an image
.TP
.B "-emboss \fI<radius>"\fP
\fRemboss an image
.TP
.B "-encoding \fI<type>"\fP
\fRspecify the text encoding
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-enhance"
\fRapply a digital filter to enhance a noisy image
.TP
.B "-equalize"
\fRperform histogram equalization to the image
.TP
.B "-extent \fI<width>x<height>{+-}<x>{+-}<y>"\fP
\fRcomposite image on background color canvas image
.TP
.B "-fill \fI<color>"\fP
\fRcolor to use when filling a graphic primitive
.TP
.B "-filter \fI<type>"\fP
\fRuse this type of filter when resizing an image
.TP
.B "-flip"
\fRcreate a "mirror image"
.TP
.B "-flop"
\fRcreate a "mirror image"
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text
.TP
.B "-format \fI<type>"\fP
\fRthe image format type
.TP
.B "-frame \fI<width>x<height>+<outer bevel width>+<inner bevel width>"\fP
\fRsurround the image with an ornamental border
.TP
.B "-fuzz \fI<distance>{%}"\fP
\fRcolors within this Euclidean distance are considered equal
.TP
.B "-gamma \fI<value>"\fP
\fRlevel of gamma correction
.TP
.B "-gaussian \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-gravity \fI<type>"\fP
\fRdirection primitive  gravitates to when annotating the image.
.TP
.B "-green-primary \fI<x>,<y>"\fP
\fRgreen chromaticity primary point
.TP
.B "-hald-clut \fI<clut>"\fP
\fRapply a Hald CLUT to the image
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-implode \fI<factor>"\fP
\fRimplode image pixels about the center
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image
.TP
.B "-lat \fI<width>x<height>{+-}<offset>{%}"\fP
\fRperform local adaptive thresholding
.TP
.B "-level \fI<black_point>{,<gamma>}{,<white_point>}{%}"\fP
\fRadjust the level of image contrast
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-linewidth"
\fRthe line width for subsequent draw operations
.TP
.B "-list \fI<type>"\fP
\fRthe type of list
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-loop \fI<iterations>"\fP
\fRadd Netscape loop extension to your GIF animation
.TP
.B "-magnify"
\fRmagnify the image
.TP
.B "-map \fI<filename>"\fP
\fRchoose a particular set of colors from this image
.TP
.B "-mask \fI<filename>"\fP
\fRSpecify a clipping mask
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-mattecolor \fI<color>"\fP
\fRspecify the color to be used with the \fB-frame\fP option
.TP
.B "-median \fI<radius>"\fP
\fRapply a median filter to the image
.TP
.B "-minify \fI<factor>"\fP
\fRminify the image
.TP
.B "-modulate \fIbrightness[,saturation[,hue]]"\fP
\fRvary the brightness, saturation, and hue of an image
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-motion-blur \fI<radius>{x<sigma>}{+angle}"\fP
\fRSimulate motion blur
.TP
.B "-negate"
\fRreplace every pixel with its complementary color
.TP
.B "-noise \fI<radius|type>"\fP
\fRadd or reduce noise in an image
.TP
.B "-noop"
\fRNOOP (no option)
.TP
.B "-normalize"
\fRtransform image to span the full range of color values
.TP
.B "-opaque \fI<color>"\fP
\fRchange this color to the pen color within the image
.TP
.B "-operator \fIchannel operator rvalue[%]"\fP
\fRapply a mathematical, bitwise, or value operator to an image channel
.TP
.B "-ordered-dither \fI<channeltype> <NxN>"\fP
\fRordered dither the image
.TP
.B "-output-directory \fI<directory>"\fP
\fRoutput files to directory
.TP
.B "-orient \fI<orientation>"\fP
\fRSet the image orientation attribute
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas
.TP
.B "-paint \fI<radius>"\fP
\fRsimulate an oil painting
.TP
.B "-pen \fI<color>"\fP
\fR(This option has been replaced by the -fill option)
.TP
.B "-pointsize \fI<value>"\fP
\fRpointsize of the PostScript, X11, or TrueType font
.TP
.B "-profile \fI<filename>"\fP
\fRadd ICM, IPTC, or generic profile  to image
.TP
.B "-preserve-timestamp"
\fRpreserve the original timestamps of the file
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
.TP
.B "-raise \fI<width>x<height>"\fP
\fRlighten or darken image edges
.TP
.B "-random-threshold \fI<channeltype> <LOWxHIGH>"\fP
\fRrandom threshold the image
.TP
.B "-recolor \fI<matrix>"\fP
\fRapply a color translation matrix to image channels
.TP
.B "-red-primary \fI<x>,<y>"\fP
\fRred chromaticity primary point
.TP
.B "-region \fI<width>x<height>{+-}<x>{+-}<y>"\fP
\fRapply options to a portion of the image
.TP
.B "-render"
\fRrender vector operations
.TP
.B "-repage \fI <width>x<height>+xoff+yoff[!]"\fP
\fRAdjust image page offsets
.TP
.B "-resample \fI<horizontal>x<vertical>"\fP
\fRResample image to specified horizontal and vertical resolution
.TP
.B "-resize \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image
.TP
.B "-roll \fI{+-}<x>{+-}<y>"\fP
\fRroll an image vertically or horizontally
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sample \fI<geometry>"\fP
\fRscale image using pixel sampling
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scale \fI<geometry>"\fP
\fRscale the image.
.TP
.B "-scene \fI<value>"\fP
\fRset scene number
.TP
.B "-set \fI<attribute> <value>"\fP
\fRset an image attribute
.TP
.B "+set \fI<attribute>"\fP
\fRunset an image attribute
.TP
.B "-segment \fI<cluster threshold>x<smoothing threshold>"\fP
\fRsegment an image
.TP
.B "-shade \fI<azimuth>x<elevation>"\fP
\fRshade the image using a distant light source
.TP
.B "-sharpen \fI<radius>{x<sigma>}"\fP
\fRsharpen the image
.TP
.B "-shave \fI<width>x<height>{%}"\fP
\fRshave pixels from the image edges
.TP
.B "-shear \fI<x degrees>x<y degrees>"\fP
\fRshear the image along the X or Y axis
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-solarize \fI<factor>"\fP
\fRnegate all pixels above the threshold level
.TP
.B "-spread \fI<amount>"\fP
\fRdisplace image pixels by a random amount
.TP
.B "-strip"
\fRremove all profiles and text attributes from the image
.TP
.B "-stroke \fI<color>"\fP
\fRcolor to use when stroking a graphic primitive
.TP
.B "-strokewidth \fI<value>"\fP
\fRset the stroke width
.TP
.B "-swirl \fI<degrees>"\fP
\fRswirl image pixels about the center
.TP
.B "-texture \fI<filename>"\fP
\fRname of texture to tile onto the image background
.TP
.B "-threshold \fI<value>{%}"\fP
\fRthreshold the image
.TP
.B "-thumbnail \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image (quickly)
.TP
.B "-tile \fI<filename>"\fP
\fRtile image when filling a graphic primitive
.TP
.B "-transform"
\fRtransform the image
.TP
.B "-transparent \fI<color>"\fP
\fRmake this color transparent within the image
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-units \fI<type>"\fP
\fRthe units of image resolution
.TP
.B "-unsharp \fI<radius>{x<sigma>}{+<amount>}{+<threshold>}"\fP
\fRsharpen the image with an unsharp mask operator
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-view \fI<string>"\fP
\fRFlashPix viewing parameters
.TP
.B "-virtual-pixel \fI<method>"\fP
\fRspecify contents of "virtual pixels"
.TP
.B "-wave \fI<amplitude>x<wavelength>"\fP
\fRalter an image along a sine wave
.TP
.B "-white-point \fI<x>,<y>"\fP
\fRchromaticity white point
.TP
.B "-white-threshold \fIred[,green][,blue][,opacity]"\fP
\fRpixels above the threshold become white

For a more detailed description of each option, see
Options, above.

.SH GM MONTAGE

\fBmontage\fP creates a composite image by combining several separate
images. The images are tiled on the composite image with the name of the
image optionally appearing just below the individual tile.

The composite image is constructed in the following manner. First, each
image specified on the command line, except for the last, is scaled to
fit the maximum tile size. The maximum tile size by default is 120x120.
It can be modified with the \fB-geometry\fP command line argument or X
resource. See
\fBOptions\fP
for more information on command line arguments. See
\fBX(1)\fP for more information on X resources.
Note that the maximum tile size need not be a square.

Next the composite image is initialized with the color specified by the
\fB-background\fP
command line argument or X resource. The width and height of the composite
image is determined by the title specified, the maximum tile size, the
number of tiles per row, the tile border width and height, the image border
width, and the label height. The number of tiles per row specifies how
many images are to appear in each row of the composite image. The default
is to have 5 tiles in each row and 4 tiles in each column of the composite.
A specific value is specified with \fB-tile\fP. The tile border width
and height, and the image border width defaults to the value of the X resource
\fB-borderwidth\fP. It can be changed with the \fB-borderwidth\fP or
\fB-geometry\fP command line argument or X resource. The label height
is determined by the font you specify with the \fB-font\fP command line
argument or X resource. If you do not specify a font, a font is chosen
that allows the name of the image to fit the maximum width of a tiled area.
The label colors is determined by the \fB-background\fP and \fB-fill\fP
command line argument or X resource. Note, that if the background and pen
colors are the same, labels will not appear.

Initially, the composite image title is placed at the top if one is specified
(refer to \fB-fill\fP). Next, each image is set onto the composite image,
surrounded by its border color, with its name centered just below it. The
individual images are left-justified within the width of the tiled area.
The order of the images is the same as they appear on the command line
unless the images have a scene keyword. If a scene number is specified
in each image, then the images are tiled onto the composite in the order
of their scene number. Finally, the last argument on the command line is
the name assigned to the composite image. By default, the image is written
in the \fBMIFF\fP format and can be viewed or printed with
\fIdisplay(1)\fP.


Note, that if the number of tiles exceeds the default number of 20 (5 per
row, 4 per column), more than one composite image is created. To ensure
a single image is produced, use \fB-tile\fP to increase the number of
tiles to meet or exceed the number of input images.

Finally, to create one or more empty spaces in the sequence of tiles, use
the \fB"NULL:"\fP image format.

Note, a composite MIFF image displayed to an X server with
\fBdisplay\fP
behaves differently than other images. You can think of the composite as
a visual image directory. Choose a particular tile of the composite and
press a button to display it. See \fBdisplay(1)\fP and \fBmiff(5)\fP
.SH EXAMPLES

To create a montage of a cockatoo, a parrot, and a hummingbird and write
it to a file called birds, use:

.nf
    gm montage cockatoo.miff parrot.miff hummingbird.miff
            birds.miff
.fi

To tile several bird images so that they are at most 256 pixels in width
and 192 pixels in height, surrounded by a red border, and separated by
10 pixels of background color, use:

.nf
    gm montage -geometry 256x192+10+10 -bordercolor red
            birds.* montage.miff
.fi

To create an unlabeled parrot image, 640 by 480 pixels, and surrounded
by a border of black, use:

.nf
    gm montage -geometry 640x480 -bordercolor black
            -label "" parrot.miff bird.miff
.fi

To create an image of an eagle with a textured background, use:

.nf
    gm montage -texture bumps.jpg eagle.jpg eagle.png
.fi

To join several GIF images together without any extraneous graphics (e.g.
no label, no shadowing, no surrounding tile frame), use:

.nf
    gm montage +frame +shadow +label -tile 5x1
            -geometry 50x50+0+0 *.png joined.png
.fi
.SH OPTIONS

Any option you specify on the command line remains in effect for the group
of images following it, until the group is terminated by the appearance of
any option or \fB-noop\fP.  For example, to make a montage of three images,
the first with 32 colors, the second with an unlimited number of colors, and
the third with only 16 colors, use:


.nf
    gm montage -colors 32 cockatoo.1 -noop cockatoo.2
             -colors 16 cockatoo.3 cockatoos.miff
.fi

For a more detailed description of each option, see
Options, above.

.TP
.B "-adjoin"
\fRjoin images into a single multi-image file
.TP
.B "-affine \fI<matrix>"\fP
\fRdrawing transform matrix
.TP
.B "-authenticate \fI<string>"\fP
\fRdecrypt image with this password
.TP
.B "-background \fI<color>"\fP
\fRthe background color
.TP
.B "-blue-primary \fI<x>,<y>"\fP
\fRblue chromaticity primary point
.TP
.B "-blur \fI<radius>{x<sigma>}"\fP
\fRblur the image with a Gaussian operator
.TP
.B "-bordercolor \fI<color>"\fP
\fRthe border color
.TP
.B "-borderwidth \fI<geometry>"\fP
\fRthe border width
.TP
.B "-chop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRremove pixels from the interior of an image
.TP
.B "-colors \fI<value>"\fP
\fRpreferred number of colors in the image
.TP
.B "-colorspace \fI<value>"\fP
\fRthe type of colorspace
.TP
.B "-comment \fI<string>"\fP
\fRannotate an image with a comment
.TP
.B "-compose \fI<operator>"\fP
\fRthe type of image composition
.TP
.B "-compress \fI<type>"\fP
\fRthe type of image compression
.TP
.B "-crop \fI<width>x<height>{+-}<x>{+-}<y>{%}"\fP
\fRpreferred size and location of the cropped image
.TP
.B "-debug \fI<events>"\fP
\fRenable debug printout
.TP
.B "-define \fI<key>{=<value>},..."\fP
\fRadd coder/decoder specific options
.TP
.B "-density \fI<width>x<height>"\fP
\fRhorizontal and vertical resolution in pixels of the image
.TP
.B "-depth \fI<value>"\fP
\fRdepth of the image
.TP
.B "-display \fI<host:display[.screen]>"\fP
\fRspecifies the X server to contact
.TP
.B "-dispose \fI<method>"\fP
\fRGIF disposal method
.TP
.B "-dither"
\fRapply Floyd/Steinberg error diffusion to the image
.TP
.B "-draw \fI<string>"\fP
\fRannotate an image with one or more graphic primitives
.TP
.B "-encoding \fI<type>"\fP
\fRspecify the text encoding
.TP
.B "-endian \fI<type>"\fP
\fRspecify endianness (MSB, LSB, or Native) of image
.TP
.B "-fill \fI<color>"\fP
\fRcolor to use when filling a graphic primitive
.TP
.B "-filter \fI<type>"\fP
\fRuse this type of filter when resizing an image
.TP
.B "-font \fI<name>"\fP
\fRuse this font when annotating the image with text
.TP
.B "-frame \fI<width>x<height>+<outer bevel width>+<inner bevel width>"\fP
\fRsurround the image with an ornamental border
.TP
.B "-gamma \fI<value>"\fP
\fRlevel of gamma correction
.TP
.B "-geometry \fI<width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}"\fP
\fRSpecify dimension, offset, and resize options.
.TP
.B "-gravity \fI<type>"\fP
\fRdirection primitive  gravitates to when annotating the image.
.TP
.B "-green-primary \fI<x>,<y>"\fP
\fRgreen chromaticity primary point
.TP
.B "-help"
\fRprint usage instructions
.TP
.B "-interlace \fI<type>"\fP
\fRthe type of interlacing scheme
.TP
.B "-label \fI<name>"\fP
\fRassign a label to an image
.TP
.B "-limit \fI<type> <value>"\fP
\fRDisk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit
.TP
.B "-log \fI<string>"\fP
\fRSpecify format for debug log
.TP
.B "-matte"
\fRstore matte channel if the image has one
.TP
.B "-mattecolor \fI<color>"\fP
\fRspecify the color to be used with the \fB-frame\fP option
.TP
.B "-mode \fI<value>"\fP
\fRmode of operation
.TP
.B "-monitor"
\fRshow progress indication
.TP
.B "-monochrome"
\fRtransform the image to black and white
.TP
.B "-noop"
\fRNOOP (no option)
.TP
.B "-page \fI<width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}"\fP
\fRsize and location of an image canvas
.TP
.B "-pen \fI<color>"\fP
\fR(This option has been replaced by the -fill option)
.TP
.B "-pointsize \fI<value>"\fP
\fRpointsize of the PostScript, X11, or TrueType font
.TP
.B "-quality \fI<value>"\fP
\fRJPEG/MIFF/PNG/TIFF compression level
.TP
.B "-red-primary \fI<x>,<y>"\fP
\fRred chromaticity primary point
.TP
.B "-render"
\fRrender vector operations
.TP
.B "-repage \fI <width>x<height>+xoff+yoff[!]"\fP
\fRAdjust image page offsets
.TP
.B "-resize \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image
.TP
.B "-rotate \fI<degrees>{<}{>}"\fP
\fRrotate the image
.TP
.B "-sampling-factor \fI<horizontal_factor>x<vertical_factor>"\fP
\fRchroma subsampling factors
.TP
.B "-scenes \fI<value-value>"\fP
\fRrange of image scene numbers to read
.TP
.B "-shadow \fI<radius>{x<sigma>}"\fP
\fRshadow the montage
.TP
.B "-sharpen \fI<radius>{x<sigma>}"\fP
\fRsharpen the image
.TP
.B "-size \fI<width>x<height>{+offset}"\fP
\fRwidth and height of the image
.TP
.B "-strip"
\fRremove all profiles and text attributes from the image
.TP
.B "-stroke \fI<color>"\fP
\fRcolor to use when stroking a graphic primitive
.TP
.B "-strokewidth \fI<value>"\fP
\fRset the stroke width
.TP
.B "-texture \fI<filename>"\fP
\fRname of texture to tile onto the image background
.TP
.B "-thumbnail \fI<width>x<height>{%}{@}{!}{<}{>}"\fP
\fRresize an image (quickly)
.TP
.B "-tile \fI<geometry>"\fP
\fRlayout of images [\fImontage\fP]
.TP
.B "-title \fI<string>"\fP
\fRassign title to displayed image [\fIanimate, display, montage\fP]
.TP
.B "-transform"
\fRtransform the image
.TP
.B "-transparent \fI<color>"\fP
\fRmake this color transparent within the image
.TP
.B "-treedepth \fI<value>"\fP
\fRtree depth for the color reduction algorithm
.TP
.B "-trim"
\fRtrim an image
.TP
.B "-type \fI<type>"\fP
\fRthe image type
.TP
.B "-verbose"
\fRprint detailed information about the image
.TP
.B "-version"
\fRprint GraphicsMagick version string
.TP
.B "-white-point \fI<x>,<y>"\fP
\fRchromaticity white point

For a more detailed description of each option, see
Options, above.

.SH X RESOURCES

\fBMontage\fP options can appear on the command line or in your X resource
file. Options on the command line supersede values specified in your X
resource file. See \fBX(1)\fP for more information on X resources.

All \fBmontage\fP options have a corresponding X resource. In addition,
\fBmontage\fP
uses the following X resources:
.TP
.B "background \fI(class Background)"\fP
\fRbackground color

Specifies the preferred color to use for the composite image background.
The default is #ccc.
.TP
.B "borderColor \fI(class BorderColor)"\fP
\fRborder color

Specifies the preferred color to use for the composite image border. The
default is #ccc.
.TP
.B "borderWidth \fI(class BorderWidth)"\fP
\fRborder width

Specifies the width in pixels of the composite image border. The default
is 2.
.TP
.B "font \fI(class Font)"\fP
\fRfont to use

Specifies the name of the preferred font to use when displaying text within
the composite image. The default is 9x15, fixed, or 5x8 determined by the
composite image size.
.TP
.B "matteColor \fI(class MatteColor)"\fP
\fRcolor of the frame

Specify the color of an image frame. A 3D effect is achieved by using highlight
and shadow colors derived from this color. The default value is #697B8F.
.TP
.B "pen \fI(class Pen)"\fP
\fRtext color

Specifies the preferred color to use for text within the composite image.
The default is black.
.TP
.B "title \fI(class Title)"\fP
\fRcomposite image title

This resource specifies the title to be placed at the top of the composite
image. The default is not to place a title at the top of the composite
image.
.SH GM TIME
.SH DESCRIPTION

\fBtime\fP executes an arbitrary \fBgm\fP utility command
(e.g. \fBconvert\fP) and reports the user and elapsed time.  This
provides way to measure command execution times similar to the Unix
\'time' command but in a portable and consistent way.
.SH EXAMPLES
To obtain time information for the execution of a
command:

.nf
% gm time convert input.ppm -gaussian 0x2 output.ppm
convert input.ppm -gaussian 0x2 output.ppm    22.60s user 0.00s system 2354% cpu 0.960 total
.fi
Here is the interpretation of the above output:

    \fBuser\fP - the total user time consumed.
    \fBsystem\fP - the total system time consumed.
    \fBtotal\fP - the total elapsed time consumed.

.SH OPTIONS
The time command reqires no options other than the gm command to
execute.
.SH GM VERSION
.SH DESCRIPTION

\fBversion\fP displays the software release version, build quantum
(pixel sample) depth, web site URL, copyright notice, enabled features
support, configuration parameters, and final build options used to
build the software.  The available information depends on how the
software was configured and the host system.
.SH EXAMPLES
To display the version information:

.nf
  GraphicsMagick 1.3.37 2021-12-12 Q16 http://www.GraphicsMagick.org/
  Copyright (C) 2002-2021 GraphicsMagick Group.
  Additional copyrights and licenses apply to this software.
  See http://www.GraphicsMagick.org/www/Copyright.html for details.
  Feature Support:
    Native Thread Safe         yes
    Large Files (> 32 bit)     yes
    Large Memory (> 32 bit)    yes
    BZIP                       yes
    DPS                        no
    FlashPix                   no
    FreeType                   yes
    Ghostscript (Library)      no
    JBIG                       yes
    JPEG-2000                  yes
    JPEG                       yes
    Little CMS                 yes
    Loadable Modules           no
    Solaris mtmalloc           no
    Google perftools tcmalloc  no
    OpenMP                     yes (201511 "4.5")
    PNG                        yes
    TIFF                       yes
    TRIO                       no
    Solaris umem               no
    WebP                       yes
    WMF                        yes
    X11                        yes
    XML                        yes
    ZLIB                       yes
  Host type: x86_64-unknown-linux-gnu
  Configured using the command:
    ./configure  ...
  Final Build Parameters:
    CC       = ...
    CFLAGS   = ...
    CPPFLAGS = ...
    CXX      = ...
    CXXFLAGS = ...
    LDFLAGS  = ...
    LIBS     = ...
.fi
.SH OPTIONS
The version command does not currently support any options.