NAME
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gm - GraphicsMagick command-line utilities to create, edit, or convert images
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Contents
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Synopsis
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gm animate [ options ... ] file [ [
options ... ] file ... ]
compare [ options ... ] reference-image
[ options ... ] compare-image
[ options ... ]
gm composite [ options ... ] change-image base-image
[ mask-image ] output-image
gm conjure [ options ] script.msl
[ [ options ] script.msl ]
gm convert [ [ options ... ] [ input-file ...
] [ options ... ] ] output-file
gm display [ options ... ] file ...
[ [options ... ]file ... ]
gm identify file [ file ... ]
gm import [ options ... ] file
gm mogrify [ options ... ] file ...
gm montage [ options ... ] file [ [
options ... ] file ... ] output-file
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Description
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GraphicsMagick's gm provides a suite of command-line
utilities for creating, converting, editing, and displaying
images:
Gm display
is a machine architecture independent
image processing and display facility. It can display an image on any workstation
display running an X server.
Gm import
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.
Gm montage
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.
Gm convert
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.
Gm mogrify
transforms an image or a sequence of
images. These transforms include image scaling, image rotation,
color
reduction, and others. The transmogrified image
overwrites the
original image.
Gm identify
describes the format and characteristics
of one or more image files. It will also report if an image is incomplete
or corrupt.
Gm composite
composites images (blends or merges images together) to create new images.
Gm conjure
interprets and executes scripts in
the Magick Scripting Language (MSL).
The GraphicsMagick utilities recognize the following image formats:
| Name | Mode | Description |
 8BIM | *rw- | Photoshop resource format |
| 8BIMTEXT | *rw- | Photoshop resource format |
| 8BIMWTEXT | *rw- | Photoshop resource format |
| APP1 | *rw- | Photoshop resource format |
| ART | *r-- | PF1: 1st Publisher |
| AVI | *r-- | Audio/Visual Interleaved |
| AVS | *rw+ | AVS X image |
| BIE | *rw- | Joint Bi-level Image experts Group |
| | | interchange format |
| BMP | *rw+ | Microsoft Windows bitmap image |
| BMP2 | *-w- | Microsoft Windows bitmap image v2 |
| BMP3 | *-w- | Microsoft Windows bitmap image v3 |
| CACHE | *--- | Magick Persistent Cache image format |
| CAPTION | *r-- | Caption (requires separate size info) |
| CIN | *rw- | Kodak Cineon Format |
| CMYK | *rw- | Raw cyan, magenta, yellow, and black |
| | | samples (8 or 16 bits, depending on |
| | | the image depth) |
| CMYKA | *rw- | Raw cyan, magenta, yellow, black, and |
| | | matte samples (8 or 16 bits, depending |
| | | on the image depth) |
| CUR | *r-- | Microsoft Cursor Icon |
| CUT | *r-- | DR Halo |
| DCM | *r-- | Digital Imaging and Communications in |
| | | Medicine image |
| DCX | *rw+ | ZSoft IBM PC multi-page Paintbrush |
| DPS | *r-- | Display PostScript |
| DPX | *rw- | Digital Moving Picture Exchange |
| EPDF | *rw- | Encapsulated Portable Document Format |
| EPI | *rw- | Adobe Encapsulated PostScript |
| | | Interchange format |
| EPS | *rw- | Adobe Encapsulated PostScript |
| EPS2 | *-w- | Adobe Level II Encapsulated PostScript |
| EPS3 | *-w- | Adobe Level III Encapsulated PostScript |
| EPSF | *rw- | Adobe Encapsulated PostScript |
| EPSI | *rw- | Adobe Encapsulated PostScript |
| | | Interchange format |
| EPT | *rw- | Adobe Encapsulated PostScript with MS-DOS |
| | | TIFF preview |
| EPT2 | *rw- | Adobe Level II Encapsulated PostScript |
| | | with MS-DOS TIFF preview |
| EPT3 | *rw- | Adobe Level III Encapsulated PostScript |
| | | with MS-DOS TIFF preview |
| EXIF | *rw- | Exif digital camera binary data |
| FAX | *rw+ | Group 3 FAX |
| FITS | *rw- | Flexible Image Transport System |
| FPX | *rw- | FlashPix Format |
| G3 | *rw- | Group 3 FAX |
| GIF | *rw+ | CompuServe graphics interchange format |
| GIF87 | *rw- | CompuServe graphics interchange format |
| | | (version 87a) |
| GRADIENT | *r-- | Gradual passing from one shade to |
| | | another |
| GRAY | *rw+ | Raw gray samples (8 or 16 bits, |
| | | depending on the image depth) |
| HISTOGRAM | *-w- | Histogram of the image |
| HTM | *-w- | Hypertext Markup Language and a |
| | | client-side image map |
| HTML | *-w- | Hypertext Markup Language and a |
| | | client-side image map |
| ICB | *rw+ | Truevision Targa image |
| ICC | *rw- | ICC Color Profile |
| ICM | *rw- | ICC Color Profile |
| ICO | *r-- | Microsoft icon |
| ICON | *r-- | Microsoft icon |
| IPTC | *rw- | IPTC Newsphoto |
| IPTCTEXT | *rw- | IPTC Newsphoto text format |
| IPTCWTEXT | *rw- | IPTC Newsphoto wide text format |
| JBG | *rw+ | Joint Bi-level Image experts Group |
| | | interchange format |
| JBIG | *rw+ | Joint Bi-level Image experts Group |
| | | interchange format |
| JNG | *rw- | JPEG Network Graphics |
| JP2 | *rw- | JPEG-2000 JP2 File Format Syntax |
| JPC | *rw- | JPEG-2000 Code Stream Syntax |
| JPEG | *rw- | Joint Photographic Experts Group |
| | | JFIF format |
| JPG | *rw- | Joint Photographic Experts Group |
| | | JFIF format |
| LABEL | *r-- | Text image format |
| LOGO | *rw- | GraphicsMagick Logo |
| M2V | *rw+ | MPEG-2 Video Stream |
| MAP | *rw- | Colormap intensities and indices |
| MAT | *r-- | MATLAB image format |
| MATTE | *-w+ | MATTE format |
| MIFF | *rw+ | Magick Image File Format |
| MNG | *rw+ | Multiple-image Network Graphics |
| MONO | *rw- | Bi-level bitmap in least-significant- |
| | | -byte-first order |
| MPC | -rw- | Magick Persistent Cache image format |
| MPEG | *rw+ | MPEG-1 Video Stream |
| MPG | *rw+ | MPEG-1 Video Stream |
| MSL | *r-- | Magick Scripting Language |
| MTV | *rw+ | MTV Raytracing image format |
| MVG | *rw- | Magick Vector Graphics |
| NULL | *r-- | Constant image of uniform color |
| OTB | *rw- | On-the-air bitmap |
| P7 | *rw+ | Xv thumbnail format |
| PAL | *rw- | 16bit/pixel interleaved YUV |
| PALM | *rw- | Palm Pixmap |
| PBM | *rw+ | Portable bitmap format (black and white) |
| PCD | *rw- | Photo CD |
| PCDS | *rw- | Photo CD |
| PCL | *-w- | Page Control Language |
| PCT | *rw- | Apple Macintosh QuickDraw/PICT |
| PCX | *rw- | ZSoft IBM PC Paintbrush |
| PDB | *rw+ | Pilot Image Format |
| PDF | *rw+ | Portable Document Format |
| PFA | *r-- | TrueType font |
| PFB | *r-- | TrueType font |
| PGM | *rw+ | Portable graymap format (gray scale) |
| PGX | *r-- | JPEG-2000 VM Format |
| PICON | *rw- | Personal Icon |
| PICT | *rw- | Apple Macintosh QuickDraw/PICT |
| PIX | *r-- | Alias/Wavefront RLE image format |
| PLASMA | *r-- | Plasma fractal image |
| PNG | *rw- | Portable Network Graphics |
| PNG24 | *rw- | Portable Network Graphics, 24 bit RGB |
| | | opaque only |
| PNG32 | *rw- | Portable Network Graphics, 32 bit RGBA |
| | | semitransparency OK |
| PNG8 | *rw- | Portable Network Graphics, 8-bit |
| | | indexed, binary transparency only |
| PNM | *rw+ | Portable anymap |
| PPM | *rw+ | Portable pixmap format (color) |
| PREVIEW | *-w- | Show a preview an image enhancement, |
| | | effect, or f/x |
| PS | *rw+ | Adobe PostScript |
| PS2 | *-w+ | Adobe Level II PostScript |
| PS3 | *-w+ | Adobe Level III PostScript |
| PSD | *rw- | Adobe Photoshop bitmap |
| PTIF | *rw- | Pyramid encoded TIFF |
| PWP | *r-- | Seattle Film Works |
| RAS | *rw+ | SUN Rasterfile |
| RGB | *rw+ | Raw red, green, and blue samples (8, 16 |
| | | or 32 bits, depending on the image depth) |
| RGBA | *rw+ | Raw red, green, blue, and matte samples |
| | | (8, 16, or 32 bits, depending on the image |
| | | depth) |
| RLA | *r-- | Alias/Wavefront image |
| RLE | *r-- | Utah Run length encoded image |
| SCT | *r-- | Scitex HandShake |
| SFW | *r-- | Seattle Film Works |
| SGI | *rw+ | Irix RGB image |
| SHTML | *-w- | Hypertext Markup Language and a |
| | | client-side image map |
| STEGANO | *r-- | Steganographic image |
| SUN | *rw+ | SUN Rasterfile |
| SVG | *rw+ | Scalable Vector Gaphics |
| TEXT | *rw+ | Raw text |
| TGA | *rw+ | Truevision Targa image |
| TIFF | *rw+ | Tagged Image File Format |
| TILE | *r-- | Tile image with a texture |
| TIM | *r-- | PSX TIM |
| TOPOL | *r-- | TOPOL X Image |
| TTF | *r-- | TrueType font |
| TXT | *rw+ | Raw text |
| UIL | *-w- | X-Motif UIL table |
| UYVY | *rw- | 16bit/pixel interleaved YUV |
| VDA | *rw+ | Truevision Targa image |
| VICAR | *rw- | VICAR rasterfile format |
| VID | *rw+ | Visual Image Directory |
| VIFF | *rw+ | Khoros Visualization image |
| VST | *rw+ | Truevision Targa image |
| WBMP | *rw- | Wireless Bitmap (level 0) image |
| WMF | *r-- | Windows Metafile |
| WPG | *r-- | Word Perfect Graphics |
| X | *rw- | X Image |
| XBM | *rw- | X Windows system bitmap (black |
| | | and white) |
| XC | *r-- | Constant image uniform color |
| XCF | *r-- | GIMP image |
| XMP | *rw- | Adobe XML metadata |
| XPM | *rw- | X Windows system pixmap (color) |
| XV | *rw+ | Khoros Visualization image |
| XWD | *rw- | X Windows system window dump (color) |
| YUV | *rw- | CCIR 601 4:1:1 or 4:2:2 (8-bit only) |
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| Modes: | | |
| | * | Native blob support |
| | r | Read |
| | w | Write |
| | + | Multi-image |
Support for some of these formats require additional programs or libraries.
README
tells where to find this software.
Note, a format delineated with + means that if more than one
image is specified, it is composited into a single multi-image file. Use
+adjoin
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 up-to-date listing of the formats supported by your particular
configuration, run "convert -list format".
Raw images are expected to have one byte per pixel unless gm
is compiled in 16-bit mode or in 32-bit mode. Here, the raw data
is expected to be stored two or four
bytes per pixel, respectively, in most-significant-byte-first order.
You can tell if gm was compiled in 16-bit mode by typing
"gm version" without any options, and looking for "Q:16" in the first line of
output.
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Files and Formats
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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 (i.e.ps:image) or specify the image type as the
filename suffix.
The magic number takes precedence over the filename suffix
and the prefix takes precedence over the magic number and the suffix
in input files.
The prefix takes precedence over the filename
suffix in output files. 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 (@).
When you specify X as your image type, the filename has special
meaning. It specifies an X window by id, name, or
root. If
no filename is specified, the window is selected by clicking the mouse
in the desired window.
Specify input_file as - for standard input,
output_file as - for standard output.
If input_file has the extension .Z or .gz, the
file is uncompressed with uncompress or gunzip
respectively.
If output_file has the extension .Z or .gz,
the file is compressed using with compress or gzip respectively.
Finally, when running on platforms that allow it, precede the image file name
with | to pipe to or from a system command (this feature is not
available on VMS, Win32 and Macintosh platforms). Use a backslash or
quotation marks to prevent your shell from interpreting the |.
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
+adjoin specified) are written with the filename followed by a
period (.) and the scene number. You can change this behavior
by embedding a %d format specification in the file name. For
example,
image%02d.miff
writes files image00.miff, image01.miff, etc. Only a single
specification is allowed within an output filename. If more than one
specification is present, it will be ignored.
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.
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Back to Contents
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Options
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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 -noop.
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 commandline options used by the
GraphicsMagick utilities (animate, compare,
composite, convert, display, identify,
import, mogrify and montage).
In this document, angle brackets ("<>") enclose variables and curly
brackets ("{}") enclose optional parameters. For example,
"-fuzz <distance>{%}" means you can use the
option "-fuzz 10"
or "-fuzz 2%".
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-adjoin
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| join images into a single multi-image file |
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By default, all images of an image sequence are stored in the same
file. However, some formats (e.g. JPEG) do not support more than one image
and are saved to separate files. Use +adjoin to force this
behavior. |
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-affine <matrix>
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This option provides a transform matrix {sx,rx,ry,sy,tx,ty} for
use by subsequent -draw or -transform options. |
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-antialias
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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. |
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-append
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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 +append to stack images left-to-right. The set of images
is terminated by the appearance of any option.
If the -append
option appears after all of the input images, all images are appended. |
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-asc-cdl <spec>
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| apply ASC CDL color transform |
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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. |
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The argument string is comma delimited and is in the following form
(but without invervening spaces or line breaks) |
redslope,redoffset,redpower:
greenslope,greenoffset,greenpower:
blueslope,blueoffset,bluepower:
saturation
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with the unity (no change) specification being:
"1.0,0.0,1.0:1.0,0.0,1.0:1.0,0.0,1.0:1.0" |
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-authenticate <string>
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| decrypt image with this password |
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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. |
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-average
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The set of images
is terminated by the appearance of any option.
If the -average
option appears after all of the input images, all images are averaged. |
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-backdrop
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| display the image centered on a backdrop. |
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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). |
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-background <color>
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The color is specified using the format described under the -fill
option. |
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-black-threshold red[,green][,blue][,opacity]
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| pixels below the threshold become black |
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Use -black-threshold 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. |
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-blue-primary <x>,<y>
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| blue chromaticity primary point |
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-blur <radius>{x<sigma>}
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| blur the image with a Gaussian operator |
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Blur with the given radius and
standard deviation (sigma). |
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-border <width>x<height>
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| surround the image with a border of color |
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See -geometry for details
about the geometry specification. |
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-bordercolor <color>
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The color is specified using the format described under the -fill
option. |
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-borderwidth <geometry>
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-box <color>
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| set the color of the annotation bounding box |
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The color is specified using the format described under the -fill
option. |
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See -draw for further
details. |
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-channel <type>
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Choose from: Red, Green, Blue, Opacity,
Matte, Cyan, Magenta, Yellow, Black,
or Gray. |
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Use this option to extract a particular channel from the image.
Opacity,
for example, is useful for extracting the opacity values from an image. |
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-charcoal <factor>
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| simulate a charcoal drawing |
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-chop <width>x<height>{+-}<x>{+-}<y>{%}
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| remove pixels from the interior of an image |
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Width and height give the number of columns and rows to remove,
and x and y are offsets that give the location of the
leftmost column and topmost row to remove. |
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The x offset normally specifies the leftmost column to remove.
If the -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the rightmost column to remove. Similarly, the y offset
normally specifies the topmost row to remove, but if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, it specifies the distance upward from the bottom edge of the
image to the bottom row to remove. |
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The -chop option removes entire rows and columns,
and moves the remaining corner blocks leftward and upward to close the gaps. |
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-clip
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| apply the clipping path, if one is present |
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If a clipping path is present, it will be applied to subsequent operations. |
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For example, if you type the following command: |
gm convert -clip -negate cockatoo.tif negated.tif
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only the pixels within the clipping path are negated. |
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The -clip feature requires the XML library. If the XML library
is not present, the option is ignored. |
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-coalesce
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| merge a sequence of images |
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Each image N in the sequence after Image 0 is replaced with the image
created by flattening images 0 through N. |
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The set of images
is terminated by the appearance of any option.
If the -coalesce
option appears after all of the input images, all images are coalesced. |
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-colorize <value>
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| colorize the image with the pen color |
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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). |
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The -colorize option may be used in conjunction with -modulate
to produce a nice sepia toned image like: |
gm convert input.ppm -modulate 115,0,100 \
-colorize 7,21,50 output.ppm.
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-colormap <type>
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Choose between shared or private. |
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This option only applies when the default X server visual is PseudoColor
or GRAYScale. Refer to -visual 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 Private and the image colors
appear exactly as they are defined. However, other clients may
go technicolor when the image colormap is installed. |
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-colors <value>
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| preferred number of colors in the image |
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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. |
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Note, options -dither, -colorspace, and -treedepth
affect the color reduction algorithm. |
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-colorspace <value>
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Choices are:
CineonLog, CMYK, GRAY, HSL, HWB,
OHTA, RGB, Rec601Luma, Rec709Luma,
Rec601YCbCr, Rec709YCbCr, Transparent, XYZ,
YCbCr, YIQ, YPbPr, or YUV. |
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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 Rec601Luma space is
based on the recommendations for legacy NTSC television (ITU-R BT.601-5).
The Rec709Luma 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 GRAY colorspace
currently selects the Rec601Luma colorspace by default for
backwards compatibly reasons. This default may be re-considered in the
future.
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| Two YCbCr colorspaces are supported. The Rec601YCbCr space is
based on the recommendations for legacy NTSC television (ITU-R BT.601-5). The
Rec709CbCr 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 YCbCr colorspace
specification is equivalent toRec601YCbCr.
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The Transparent color space behaves uniquely in that it preserves
the matte channel of the image if it exists. |
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The -colors or -monochrome option, or saving to a file
format which requires color reduction, is required for this option to
take effect. |
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-comment <string>
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| annotate an image with a comment |
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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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
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produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
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If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
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-compose <operator>
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| the type of image composition |
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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 opaque pixel is fully visible while the color of a
transparent pixel color is entirely absent (pixel color is ignored). |
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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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent 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 Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
|
The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
|
-compress <type>
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
|
"Lossless" 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 -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
|
-contrast
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
For a more pronounced effect you can repeat the option: |
gm convert rose: -contrast -contrast rose_c2.png
|
-convolve <kernel>
|
| convolve 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. |
|
-create-directories
|
| create output directory if required |
|
Use this option with -output-directory if the input paths contain
subdirectories and it is desired to create similar subdirectories in the
output directory. Without this option, mogrify will fail if the
required output directory does not exist. |
|
-crop <width>x<height>{+-}<x>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -geometry for details
about the geometry specification. |
|
The width and height give the size of the image that remains after cropping,
and x and y 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 -shave instead. |
|
If the x and y 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 -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edgesoption 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 -format 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 -draw option. |
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480. |
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string. |
|
-compose <operator>
|
| the 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 opaque pixel is fully visible while the color of a
transparent pixel color is entirely absent (pixel color is ignored). |
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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. |
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By default, the Over composite operator is used. The following
composite operators are available: |
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Divide
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
CopyCyan
CopyMagenta
CopyYellow
CopyBlack
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The behavior of each operator is described below. |
- Over
- The result will be the union of the two image shapes, with opaque areas
of change-image obscuring base-image in the region of
overlap.
- In
- The result is simply change-image cut by the shape of
base-image. None of the image data of base-image will be in
the result.
- Out
- The resulting image is change-image with the shape of
base-image cut out.
- Atop
- The result is the same shape as base-image, with
change-image obscuring base-image where the image shapes
overlap. Note this differs from over because the portion of
change-image outside base-image's shape does not appear in
the result.
- Xor
- The result is the image data from both change-image and
base-image that is outside the overlap region. The overlap region
will be blank.
- Plus
- 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.
- Minus
- The result of change-image - base-image, with underflow
cropped to zero. The matte channel is ignored (set to opaque, full
coverage).
- Add
- The result of change-image + base-image, with overflow
wrapping around (mod MaxRGB+1).
- Subtract
- The result of change-image - base-image, with underflow
wrapping around (mod MaxRGB+1). The add and subtract
operators can be used to perform reversible transformations.
- Difference
- The result of abs(change-image - base-image). This is
useful for comparing two very similar images.
- Divide
- The result of change-image / base-image. 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).
- Multiply
- The result of change-image * base-image. This is useful for
the creation of drop-shadows.
- Bumpmap
- The result base-image shaded by change-image.
- Copy
- The resulting image is base-image replaced with
change-image. Here the matte information is ignored.
- CopyRed
- The resulting image is the red channel in base-image replaced with
the red channel in change-image. The other channels are copied
untouched.
- CopyGreen
- The resulting image is the green channel in base-image replaced
with the green channel in change-image. The other channels are
copied untouched.
- CopyBlue
- The resulting image is the blue channel in base-image replaced
with the blue channel in change-image. The other channels are
copied untouched.
- CopyOpacity
- The resulting image is the opacity channel in base-image replaced
with the opacity channel in change-image. The other channels are
copied untouched.
- CopyCyan
- The resulting image is the cyan channel in base-image replaced
with the cyan channel in change-image. The other channels are
copied untouched. Use of this operator requires that base-image be in
CMYK(A) colorspace.
- CopyMagenta
- The resulting image is the magenta channel in base-image
replaced with the magenta channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyYellow
- The resulting image is the yellow channel in base-image
replaced with the yellow channel in change-image. The other
channels are copied untouched. Use of this operator requires that
base-image be in CMYK(A) colorspace.
- CopyBlack
- The resulting image is the black channel in base-image
replaced with the black channel in change-image. 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.
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-compress <type>
|
| the type of image compression |
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Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
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Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file. |
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"Lossless" 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. |
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Use the -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor
option to set the sampling factor to be used by the DPX, JPEG, MPEG, and
YUV encoders for downsampling the chroma channels. |
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