4ImageMagick Image Compositing Utility9BF3
PCombine

 


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8 M >Contents











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8 M >Synopsis




:

combine [ options ... ] image6composite [ mask ] combined


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8 M >Description




7

combine combine images to create new images.


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8 M >Examples




8

To combine an image of a cockatoo with a perch, use:
A

combine cockatoo.miff perch.ras composite.miff



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

combine -compose difference series.1 series.2 difference.miff



>
To combine an image of a cockatoo with a perch starting atlocation (100,150), use:
X

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



7
To tile a logo across your image of a cockatoo, use
<

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



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

combine -compose ReplaceGreen red.png green.png red-green.pngQ
combine -compose ReplaceBlue red-green.png blue.png composite.png






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8 M >Options




@

Options are processed in command line order. Any option you9specify on the command line remains in effect until it is8explicitly changed by specifying the option again with adifferent effect.



2
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8 M >-blend value

)
blend the two images a given percent.



º
>-cache.threshold
<
megabytes of memory available to the pixel cache.


B

Image pixels are stored in memory until 80 megabytes of memoryDhave been consumed. Subsequent pixel operations are cached on disk.KOperations to memory are significantly faster but if your computer does notMhave a sufficient amount of free memory you may want to adjust this threshold value.

2
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8 M >-colors value
,
preferred number of colors in the image.

8

The actual number of colors in the image may be less3than your request, but never more. Note, this is a7color reduction option. Images with less unique colors7than specified with this option will have any duplicateor unused colors removed.>Refer to quantize(9)for more details.

K

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

2

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8 M >-colorspace value
A
the type of colorspace: GRAY, OHTA, RGB,HTransparent, XYZ, YCbCr, YIQ, YPbPr, YUV, or CMYK.

7

Color reduction, by default, takes place in the RGB.color space. Empirical evidence suggests that7distances in color spaces such as YUV or YIQ correspond4to perceptual color differences more closely than do4distances in RGB space. These color spaces may give6better results when color reducing an image. Refer to$quantize(9) for more details.

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

DThe -colors or -monochrome option is required for thisoption to take effect.

2

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8 M >-comment string
%
annotate an image with a comment.

5

By default, each image is commented with its file3name. Use this option to assign a specific comment3to the image. Optionally you can include the image:filename, type, width, height, or other image attribute by$embedding special format characters:

    %b   file size    %d   directory    %e   filename extention    %f   filename    %h   height    %i   input filename    %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"
I
produces an image comment of MIFF:bird.miff 512x480 for;an image titled bird.miff and whose width is 512 andheight is 480.

D

If the first character of string is @, the image3comment is read from a file titled by the remainingcharacters in the string.

2

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8 M >-compose operator
"
the type of image composition.

6

By default, each of the composite image pixels are7replaced by the corresponding image tile pixel. You can(choose an alternate composite operation.-How each operator behaves is described below.




2
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8 M >over
>
The result will be the union of the two image shapes, withKcomposite image obscuring image in the region of overlap.

2

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8 M >in
E
The result is simply composite image cut by the shape ofHimage. None of the image data of image will be in theresult.

2

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8 M >out
E
The resulting image is composite image with the shape ofimage cut out.

2

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8 M >atop
>
The result is the same shape as image image, withHcomposite image obscuring image where the image shapesCoverlap. Note this differs from over because the portion ofcomposite image=outside image's shape does not appear in the result.

2

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8 M >xor
G
The result is the image data from both composite image andFimage that is outside the overlap region. The overlap regionwill be blank.

2

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8 M >plus
L
The result is just the sum of the image data. Output values are croppedAto 255 (no overflow). This operation is independent of the matte channels.

2

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8 M >minus
K
The result of composite image - image, with underflowKcropped to zero. The matte channel is ignored (set to 255, full coverage).

2

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8 M >add
J
The result of composite image + image, with overflow#wrapping around (mod 256).

2

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8 M >subtract
K
The result of composite image - image, with underflowGwrapping around (mod 256). The add and subtract<operators can be used to perform reversible transformations.

2

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8 M >difference
J
The result of abs(composite image - image). This is-useful for comparing two very similar images.

2

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8 M >bumpmap
:
The result of image shaded by image.

2

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8 M >replace
7
The resulting image is image replaced with@composite image. Here the matte information is ignored.




B
The image compositor requires a matte, or alpha channel in the6image for some operations. This extra channel usuallyNdefines a mask which represents a sort of a cookie-cutter for the image. ThisOis the case when matte is 255 (full coverage) for pixels inside the shape, zeroKoutside, and between zero and 255 on the boundary. For certain operations,if image does notHhave a matte channel, it is initialized with 0 for any pixel matching in>color to pixel location (0,0), otherwise 255 (to work properlyborderwidth must be 0).

2

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8 M >-compress type
H
the type of image compression: None, BZip, Fax,NGroup4, JPEG, LZW, RunlengthEncoded or Zip.

<

Specify +compress to store the binary image in an4uncompressed format. The default is the compression!type of the specified image file.

2

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8 M >-density <width>x<height>
>
vertical and horizontal resolution in pixels of the image.

:

This option specifies an image density when decoding a5Postscript or Portable Document page. The default is172 pixels per inch in the horizontal and vertical<direction. This option is used in concert with -page

2

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8 M >-displace<horizontal scale>x<vertical scale>
8
shift image pixels as defined by a displacement map.

K

With this option, composite image is used as a displacement map.NBlack, within the displacement map, is a maximum positive displacement. WhitePis a maximum negative displacement and middle gray is neutral. The displacementMis scaled to determine the pixel shift. By default, the displacement appliesHin both the horizontal and vertical directions. However, if you specifyHmask, composite image is the horizontal X displacement and(mask the vertical Y displacement.

2

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8 M >-display host:display[.screen]
7
specifies the X server to contact; see X(1).

2

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8 M >-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.


2

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8 M >-dither
7
apply Floyd/Steinberg error diffusion to the image.

9

The basic strategy of dithering is to trade intensity2resolution for spatial resolution by averaging the2intensities of several neighboring pixels. Images1which suffer from severe contouring when reducing(colors can be improved with this option.

C

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

M

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

2

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8 M >-font name
2
This option specifies the font to be used fordisplaying normal text.

M

If the font is a fully qualified X server font name, the font is obtainedfrom an X server (e.g.?-*-helvetica-medium-r-*-*-12-*-*-*-*-*-iso8859-*). ToJuse a TrueType font, precede the TrueType filename with a @ (e.g.A@times.ttf). Otherwise, specify a Postscript font (e.g.helvetica).

2

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8 M >-geometry <width>x<height>{+-}<x offset>{+-}<y offset>{%}{!}{<}{>}
&
the width and height of the image.

8

By default, the width and height are maximum values.7That is, the image is expanded or contracted to fit the3width and height value while maintaining the aspect7ratio of the image. Append an exclamation point to the4geometry to force the image size to exactly the size=you specify. For example, if you specify 640x480! the7image width is set to 640 pixels and height to 480. If7only one factor is specified, both the width and heightassume the value.

;

To specify a percentage width or height instead, append8%. The image size is multiplied by the width and,height percentages to obtain the final image4dimensions. To increase the size of an image, use a3value greater than 100 (e.g. 125%). To decrease an-image's size, use a percentage less than 100.

9

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, if1the image is 1024x1024, it is resized to 640x480.

D

By default the images are combined relative to the image gravity@(see -gravity). Use <x offset> andD<y offset> to specify a particular location tocombine the images. 

2

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8 M >-gravity type
J
direction image gravitates to within the composite: NorthWest, North,;NorthEast, West, Center, East, SouthWest, South, SouthEast.5See X(1) for details about the gravity specification.

0

The direction you choose specifies where toMposition the image within the composite. For example Center gravity5forces the image to be centered within the composite.4By default, the image gravity is NorthWest.

2

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8 M >-interlace type
K
the type of interlacing scheme: None, Line, Plane,1or Partition. The default is None.

I

This option is used to specify the type of interlacing scheme for rawIimage formats such as RGB or YUV. None means do notHinterlace (RGBRGBRGBRGBRGBRGB...), Line uses scanline interlacingC(RRR...GGG...BBB...RRR...GGG...BBB...), and Plane uses planeLinterlacing (RRRRRR...GGGGGG...BBBBBB...). Partition is like planeIexcept the different planes are saved to individual files (e.g. image.R,image.G, and image.B).

H

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

2

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8 M >-label name

assign a label to an image.

5

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 byEembedding special format character. See -comment for details.





For example,
    -label "%m:%f %wx%h"
G
produces an image label of MIFF:bird.miff 512x480 for;an image titled bird.miff and whose width is 512 andheight is 480.

J

If the first character of string is @, the image label6is read from a file titled by the remaining charactersin the string.

5

When converting to Postscript, use this option to1specify a header string to print above the image.

2

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8 M >-matte
L
store matte channel if the image has one otherwise create an opaque one.

2

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8 M >-monochrome
+
transform the image to black and white.

2

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8 M >-negate
J
replace every pixel with its complementary color (white becomes black,yellow becomes blue, etc.).

8

The red, green, and blue intensities of an image areGnegated. Use +negate to only negate the grayscale pixels of theimage.

2

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8 M >-page <width>x<height>{+-}<x offset>{+-}<y offset>{%}{!}{<}{>}
)
size and location of an image canvas.

4

Use this option to specify the dimensions of the9PostScript 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 mediaC(e.g. A4, Ledger, etc.). Otherwise, -page behaves much like7-geometry (e.g. -page letter+43+43>).

-

To position a GIF image, use -page/{+-}<x offset>{+-}<y offset>(e.g. -page "+1"00+200).

H

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

<

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

8

This option is used in concert with -density.

2

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8 M >-quality value
$
JPEG/MIFF/PNG compression level.

C

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

T

Quality for the MIFF and PNG image format sets the amount of image compression C(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.

9

If filter-type is 6 or more, adaptive filtering with 0minimum-sum-of-absolute-values is used.

J

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

%

For further information, see the =PNG specification.

2

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8 M >-scene value

image scene number.

2

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8 M >-size <width>{%}x<height>{%}{+offset}{!}
"
width and height of the image.

:

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

2

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8 M >-stegano
#
hide watermark within an image.

J

Use an offset to start the image hiding some number of pixels from theGbeginning of the image. Note this offset and the image size. You will9need this information to recover the steganographic image;(e.g. display -size 320x256+35 stegano:image.png).

2

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8 M >-stereo
2
combine two image to create a stereo anaglyph.

8

The left side of the stereo pair is saved as the red5channel of the output image. The right sife is saved2as the green channel. Red-blue stereo glasses are+required to properly view the stereo image.

2

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8 M >-tile
,
repeat composite operation across image.

2

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8 M >-treedepth value
;
Normally, this integer value is zero or one. A zero or<one tells combine to choose an optimal tree depth forthe color reduction algorithm.

.

An optimal depth generally allows the best3representation of the source image with the fastest3computational speed and the least amount of memory.4However, the default depth is inappropriate for some6images. To assure the best representation, try values-between 2 and 8 for this parameter. Refer to$quantize(9) for more details.

A

The -colors option is required for this option to takeeffect.

2

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8 M >-verbose
/
print detailed information about the image.

;

This information is printed: image scene number; image3name; combined image name; image size; the imageGclass (DirectClass or PseudoClass); the total number4of unique colors; and the number of seconds to readand combine the image.


;

By default, the image format is determined by its magic9number. To specify a particular image format, precede the4filename with an image format name and a colon (i.e.:ps:image) or specify the image type as the filename suffixA(i.e. image.ps). See convert(1) for a list of valid imageformats.

B

When you specify X as your image type, the filename has:special meaning. It specifies an X window by id, name, orAroot. If no filename is specified, the window is selected,by clicking the mouse in the desired window.

3

Specify image as - for standard input,Bcombined as - for standard output. If image hasDthe extension .Z or .gz, the file is uncompressed withFuncompress or gunzip respectively. If combinedFhas the extension .Z or .gz, the file size is compressedIusing with compress or gzip respectively. Finally, precede?the image file name with | to pipe to or from a system command.

K

Use an optional index enclosed in brackets after a file name to specifyCa desired subimage of a multi-resolution image format like Photo CDI(e.g. img0001.pcd[4]) or a range for MPEG images (e.g. video.mpg[50-75]).BA subimage specification can be disjoint (e.g. image.tiff[2,7,4]).GFor raw images, specify a subimage with a geometry (e.g. -size 640x512image.rgb[320x256+50+50]).

EThe optional mask can be used to provide matte information forBcomposite when it has none or if you want a different mask.9A mask image is typically grayscale and the same size as Dcomposite. If the image is not grayscale, it is converted toFgrayscale and the resulting intensities are used as matte information.

C

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

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8 M >Environment






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8 M >DISPLAY
8
To get the default host, display number, and screen.



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8 M >Authors




C

John Cristy, L magick@wizards.dupont.com E.I. du Pont de Nemours and CompanyIncorporated.


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8 M >Copyright


)

Copyright (C) 2000 ImageMagick Studio

K

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

O

The above copyright notice and this permission notice shall be included in 3all copies or substantial portions of ImageMagick. 

O

The software is provided "as is", without warranty of any kind, express or Iimplied, including but not limited to the warranties of merchantability, Gfitness for a particular purpose and noninfringement.In no event shall 7ImageMagick Studio be liable for any claim, damages or Eother liability, whether in an action of contract, tort or otherwise,Karising from, out of or in connection with ImageMagick or the use or other dealings in ImageMagick. 

I

Except as contained in this notice, the name of the E. I. du Pont de ENemours and Company shall not be used in advertising or otherwise to Epromote the sale, use or other dealings in ImageMagick without prior 3written authorization from the ImageMagick Studio. 


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