> NAME

import - capture some or all of an X server screen and save the image to a file.
> Contents

Synopsis
Description
Examples
Options
Environment
Authors
Copyright
> Synopsis

composite [ options ... ] imagecomposite [ mask ] composited

> Description

composite composite images to create new images.

> Examples

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

    composite cockatoo.miff perch.ras composite.miff

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

    composite -compose difference series.1 series.2 \
              difference.miff

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

    composite -geometry "+1"00"+1"50 cockatoo.miff \
              perch.ras composite.miff

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

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

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

    composite -compose CopyGreen red.png green.png \
              red-green.png
    composite -compose CopyBlue red-green.png blue.png \
              composite.png

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> Options

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


> -background color

the background color

> -cache threshold

megabytes of memory available to the pixel cache

Image pixels are stored in memory until 80 megabytes of memory have been consumed. Subsequent pixel operations are cached on disk. Operations to memory are significantly faster but if your computer does not have a sufficient amount of free memory you may want to adjust this threshold value.

> -colors value

preferred number of colors in the image

The actual number of colors in the image may be less than your request, but never more. Note, this is a color reduction option. Images with less unique colors than specified with this option will have any duplicate or unused colors removed. Refer to quantize for more details.

Note, options -dither, -colorspace, and -treedepth affect the color reduction algorithm.

> -colorspace value

the type of colorspace

Choices are: GRAY, OHTA, RGB, Transparent, XYZ, YCbCr, YIQ, YPbPr, YUV, or CMYK.

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.

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

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

> -comment string

annotate an image with a comment

Use this option to assign a specific comment to the image. You can include the image filename, type, width, height, or other image attribute by embedding special format characters:
     %b   file size
     %c   comment
     %d   directory
     %e   filename extention
     %f   filename
     %h   height
     %i   input filename
     %k   number of unique colors
     %l   label
     %m   magick
     %n   number of scenes
     %o   output filename
     %p   page number
     %q   quantum depth
     %s   scene number
     %t   top of filename
     %u   unique temporary filename
     %w   width
     %x   x resolution
     %y   y resolution
     \n   newline
     \r   carriage return

For example,
     -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

By default, each of the composite image pixels are replaced by the corresponding image tile pixel. You can choose an alternate composite operation:
     Over
     In
     Out
     Atop
     Xor
     Plus
     Minus
     Add
     Subtract
     Difference
     Multiply
     Bumpmap
     Copy
     CopyRed
     CopyGreen
     CopyBlue
     CopyOpacity

How each operator behaves is described below.
Over
The result will be the union of the two image shapes, with opaque areas of composite image obscuring image in the region of overlap.
In
The result is simply composite image cut by the shape of image. None of the image data of image will be in the result.
Out
The resulting image is composite image with the shape of image cut out.
Atop
The result is the same shape as image image, with composite image obscuring image where the image shapes overlap. Note this differs from over because the portion of composite image outside image's shape does not appear in the result.
Xor
The result is the image data from both composite image and 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 255 (no overflow). This operation is independent of the matte channels.
Minus
The result of composite image - image, with underflow cropped to zero. The matte channel is ignored (set to 255, full coverage).
Add
The result of composite image + image, with overflow wrapping around (mod 256).
Subtract
The result of composite image - image, with underflow wrapping around (mod 256). The add and subtract operators can be used to perform reversible transformations.
Difference
The result of abs(composite image - image). This is useful for comparing two very similar images.
Multiply
The result of composite image * image. This is useful for the creation of drop-shadows.
Bumpmap
The result image shaded by composite image.
Copy
The resulting image is image replaced with composite image. Here the matte information is ignored.
CopyRed
The resulting image is the red layer in image replaced with the red layer in composite image. The other layers are copied untouched.
CopyGreen
The resulting image is the green layer in image replaced with the green layer in composite image. The other layers are copied untouched.
CopyBlue
The resulting image is the blue layer in image replaced with the blue layer in composite image. The other layers are copied untouched.
CopyOpacity
The resulting image is the matte layer in image replaced with the matte layer in composite image. The other layers are copied untouched.

The image compositor requires a matte, or alpha channel in the image for some operations. This extra channel usually defines a mask which represents a sort of a cookie-cutter for the image. This is the case when matte is 255 (full coverage) for pixels inside the shape, zero outside, and between zero and 255 on the boundary. For certain operations, if image does not have a matte channel, it is initialized with 0 for any pixel matching in color to pixel location (0,0), otherwise 255 (to work properly borderwidth must be 0).

> -compress type

the type of image compression

Choices are: None, BZip, Fax, Group4, JPEG, 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.

> -debug

enable debug printout

> -density <width>x<height>

vertical and horizontal resolution in pixels of the image

This option specifies an image density when decoding a PostScript or Portable Document page. The default is 72 dots per inch in the horizontal and vertical direction. This option is used in concert with -page.

> -depth value

depth of the image

This is the number of bits in a pixel. The only acceptable values are 8 or 16. Use this option to specify the depth of raw images whose depth is unknown such as GRAY, RGB, or CMYK, or to change the depth of any image after it has been read.

> -displace <horizontal scale>x<vertical scale>

shift image pixels as defined by a displacement map

With this option, composite image is used as a displacement map. Black, within the displacement map, is a maximum positive displacement. White is a maximum negative displacement and middle gray is neutral. The displacement is scaled to determine the pixel shift. By default, the displacement applies in both the horizontal and vertical directions. However, if you specify mask, composite image is the horizontal X displacement and mask the vertical Y displacement.

> -display host:display[.screen]

specifies the X server to contact

> -dispose method

GIF disposal method

Here are the valid methods:
     0     No disposal specified.
     1     Do not dispose between frames.      
     2     Overwrite frame with background color from header.
     3     Overwrite with previous frame.

> -dissolve value

dissolve an image

> -dither

apply Floyd/Steinberg error diffusion to the image

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

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

Use +dither to render Postscript without text or graphic aliasing.

> -filter type

use this type of filter when resizing an image

Use this option to affect the resizing operation of an image (see -geometry). Choose from these filters:
     Point
     Box
     Triangle
     Hermite
     Hanning
     Hamming
     Blackman
     Gaussian
     Quadratic
     Cubic
     Catrom
     Mitchell
     Lanczos
     Bessel
     Sinc

The default filter is Lanczos

> -font name

use this font when annotating the image with text

You can tag a font to specify whether it is a Postscript, Truetype, or OPTION1 font. For example, Arial.ttf is a Truetype font, ps:helvetica is Postscript, and x:fixed is OPTION1.

> -geometry <width>x<height>{+-}<x offset>{+-}<y offset>{%}{@}{!}{<}{>}

preferred size and location of the Image window.

See X(1) for details about the geometry specification. By default, the window size is the image size and the location is chosen by you when it is mapped.

By default, the width and height are maximum values. That is, the image is expanded or contracted to fit the width and height value while maintaining the aspect ratio of the image. Append an exclamation point to the geometry to force the image size to exactly the size you specify. For example, if you specify 640x480! the image width is set to 640 pixels and height to 480. If only one factor is specified, both the width and height assume the value.

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

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

Use > to change the dimensions of the image only if its size exceeds the geometry specification. < resizes the image only if its dimensions is less than the geometry specification. For example, if you specify '640x480>' and the image size is 512x512, the image size does not change. However, if the image is 1024x1024, it is resized to 640x480.

Use < to change the dimensions of the image only if its size exceeds the geometry specification. > resizes the image only if its dimensions is less than the geometry specification. For example, if you specify 640x480> and the image size is 512x512, the image size does not change. However, if the image is 1024x1024, it is resized to 640x480.

There are 72 pixels per inch in PostScript coordinates.

> -gravity type

direction text gravitates to when annotating the image.

Choices are: NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast. See X(1) for details about the gravity specification.

The direction you choose specifies where to position the text when annotating the image. For example Center gravity forces the text to be centered within the image. By default, the image gravity is NorthWest.

> -help

print usage instructions

> -interlace type

the type of interlacing scheme

Choices are: None, Line, Plane, or Partition. The default is None.

This option is used to specify the type of interlacing scheme for raw image formats such as RGB or YUV. None means do not interlace (RGBRGBRGBRGBRGBRGB...), Line uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and Plane uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...). Partition is like plane except the different planes are saved to individual files (e.g. image.R, image.G, and image.B).

Use Line, or Plane to create an interlaced PNG or GIF or progressive JPEG image.

> -label name

assign a label to an image

Use this option to assign a specific label to the image. Optionally you can include the image filename, type, width, height, or other image attribute by embedding special format character. See -comment for details.

For example,
     -label "%m:%f %wx%h"

produces an image label 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 label is read from a file titled by the remaining characters in the string.

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

> -matte

store matte channel if the image has one

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

> -monochrome

transform the image to black and white

> -negate

replace every pixel with its complementary color

The red, green, and blue intensities of an image are negated. White becomes black, yellow becomes blue, etc. Use +negate to only negate the grayscale pixels of the image.

> -page <width>x<height>{+-}<x offset>{+-}<y offset>{%}{!}{<}{>}

size and location of an image canvas

Use this option to specify the dimensions of the PostScript page in dots per inch or a TEXT page in pixels. The choices for a Postscript page are:
     11x17         792  1224 
     Ledger       1224   792    
     Legal         612  1008
     Letter        612   792
     LetterSmall   612   792
     ArchE        2592  3456
     ArchD        1728  2592
     ArchC        1296  1728
     ArchB         864  1296
     ArchA         648   864
     A0           2380  3368
     A1           1684  2380
     A2           1190  1684
     A3            842  1190
     A4            595   842
     A4Small       595   842
     A5            421   595
     A6            297   421
     A7            210   297
     A8            148   210
     A9            105   148
     A10            74   105
     B0           2836  4008
     B1           2004  2836
     B2           1418  2004
     B3           1002  1418
     B4            709  1002
     B5            501   709
     C0           2600  3677
     C1           1837  2600
     C2           1298  1837
     C3            918  1298
     C4            649   918
     C5            459   649
     C6            323   459
     Flsa          612   936 
     Flse          612   936
     HalfLetter    396   612

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

To position a GIF image, use -page{+-}<x offset>{+-}<y offset> (e.g. -page +100+200).

For a Postscript page, the image is sized as in -geometry and positioned relative to the lower left hand corner of the page by {+-}<xoffset>{+-}<y offset>. Use -page 612x792>, for example, to center the image within the page. If the image size exceeds the Postscript page, it is reduced to fit the page.

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

This option is used in concert with -density.

> -profile filename

add ICM color or IPTC newswire information profile to image

Use +profile icm or +profile iptc to remove the respective profile.

> -quality value

JPEG/MIFF/PNG compression level

For the JPEG image format, quality is 0 (worst) to 100 (best). The default quality is 75.

Quality for the MIFF and PNG image format sets the amount of image compression (quality / 10) and filter-type (quality % 10). Compression quality values range from 0 (worst) to 100 (best). If filter-type is 4 or less, the specified filter-type is used for all scanlines:
     0: none
     1: sub
     2: up
     3: average
     4: Paeth

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

If filter-type is 6 or more, adaptive filtering with minimum-sum-of-absolute-values is used.

The default is quality is 75. Which means nearly the best compression with adaptive filtering.

For further information, see the PNG specification.

> -rotate degrees{<}{>}

apply Paeth image rotation to the image

Use > to rotate the image only if its width exceeds the height. < rotates the image only if its width is less than the height. For example, if you specify -90> and the image size is 480x640, the image is not rotated by the specified angle. However, if the image is 640x480, it is rotated by -90 degrees.

Empty triangles left over from rotating the image are filled with the color defined as background (class backgroundColor). See X(1) for details.

> -scene value{-value}

image scene number or range

Use this option to specify an image sequence with a single filename. See the discussion of file below for details.

> -size <width>x<height>{+offset}

width and height of the image

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

For Photo CD images, choose from these sizes:
     192x128
     384x256
     768x512
     1536x1024
     3072x2048

Finally, use this option to choose a particular resolution layer of a JBIG or JPEG image (e.g. -size 1024x768).

> -stackdrop file

stack some images in "drop" mode

This feature is untested.

> -stackreplace file

stack some images in "replace" mode

This feature is untested.

> -treedepth value

tree depth for the color reduction algorithm

Normally, this integer value is zero or one. A zero or one tells display to choose an optimal tree depth for the color reduction algorithm

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

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

> -type type

the image type

Choose from: Bilevel, Grayscale, Palette, PaletteMatte, TrueColor, TrueColorMatte, ColorSeparation, ColorSeparationMatte, or Optimize.

> -units type

the type of image resolution

Choose from: Undefined, PixelsPerInch, or PixelsPerCentimeter.

> -unsharp <radius>x<sigma>

sharpen the image with an unsharp mask operator

Use the given radius and standard deviation (sigma).

> -verbose

print detailed information about the image

This information is printed: image scene number; image name; image size; the image class (DirectClass or PseudoClass); the total number of unique colors; and the number of seconds to read and transform the image. Refer to miff for a description of the image class.

If -colors is also specified, the total unique colors in the image and color reduction error values are printed. Refer to quantize for a description of these values.

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> Files and Formats

By default, the image format is determined by its magic number. 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 (i.e. image.ps). See convert(1) for a list of valid image formats.

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 image as - for standard input, composited as - for standard output. If image has the extension .Z or .gz, the file is uncompressed with uncompress or gunzip respectively. If composited has the extension .Z or .gz, the file size is compressed using with compress or gzip respectively. Finally, precede the image file name with | to pipe to or from a system command.

Use an optional index enclosed in brackets after a 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]).

The optional mask can be used to provide matte information for composite when it has none or if you want a different mask. A mask image is typically grayscale and the same size as composite. If the image is not grayscale, it is converted to grayscale and the resulting intensities are used as matte information.

If composited already exists, you will be prompted as to whether it should be overwritten.

> Environment


> DISPLAY

To get the default host, display number, and screen.

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>Authors
John Cristy, magick-users@imagemagick.org, ImageMagick Studio LLC.
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>Copyright
Copyright (C) 2002 ImageMagick Studio

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files ("ImageMagick"), to deal in ImageMagick without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of ImageMagick, and to permit persons to whom the ImageMagick is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of ImageMagick.

The software is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement.In no event shall ImageMagick Studio be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with ImageMagick or the use or other dealings in ImageMagick.

Except as contained in this notice, the name of the ImageMagick Studio LLC shall not be used in advertising or otherwise to promote the sale, use or other dealings in ImageMagick without prior written authorization from the ImageMagick Studio.

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