4ImageMagick Image Compositing Utility4NF,
B

 


Contents





Synopsis

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


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Description

7
combine combine images to create new images.


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Examples

7
To combine a 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 a image of a cockatoo with a perch starting atlocation (100,150), use:
T

combine -geometry +100+150 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

a

combine -compose bumpmap -tile logo.gif cockatoo.miff mask.miff composite.miff






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Options 


-blend value)
blend the two images a given percent.

!

-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 colors6than specified with this option will remain unchanged.>Refer to quantize(9)for more details.

K

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

%

-colorspace valueA
the type of colorspace: GRAY, OHTA, RGB,JTransparent, XYZ, YCbCr, YIQ, YPbPr, or YUV.

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.

#

-comment string%
annotate an image with a comment.

;

By default, each image is commented with its file name.3Use this option to assign a specific comment to the6image. Optionally you can include the image filename,1type, width, height, or scene number by embeddingCspecial format characters. Embed %f for filename, %mJfor magick, %w for width, %h for height, %s for scene/number, or \n for newline. 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.

%

-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.





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

inE
The result is simply composite image cut by the shape ofHimage. None of the image data of image will be in theresult.



outE
The resulting image is composite image with the shape ofimage cut out.



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.



xorG
The result is the image data from both composite image andFimage that is outside the overlap region. The overlap regionwill be blank.



plusL
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.



minusK
The result of composite image - image, with underflowKcropped to zero. The matte channel is ignored (set to 255, full coverage).



addJ
The result of composite image + image, with overflow#wrapping around (mod 256).



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



differenceJ
The result of abs(composite image - image). This is-useful for comparing two very similar images.



bumpmap:
The result of image shaded by image.



replace7
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 notIhave an 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).

"

-compress type2
the type of image compression: Zip orRunlengthEncoded.

<

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

I

-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.



-displaceJ <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.

D

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

!

-dispose method
GIF disposal method.

P

See Graphics Interchange Format (GIF) Specification 89a of July 31, 1990 fordetails.



-dither7
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.

?

The -colors option is required for dithering to takeeffect.



-font name2
This option specifies the font to be used for5displaying normal text. The default is fixed.

w

-geometry <width>{%}x<height>{%}{+-}<x offset>{+-0}<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. 

&

-gravity directionM
direction image gravitates to within the composite. See X(1) for(details about the gravity specification.

8

The image may not fill the composite completely (see?-geometry). The direction you choose specifies where toMposition the image within the composite. For example Center gravityCforces the image to be centered within the composite. A gravity ofDForget stretches the composite to the same size as the image.4By default, the image gravity is NorthWest.

#

-interlace typeK
the type of interlacing scheme: None, Line, Plane,2or Partition. The default is Plane.

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.



-label name
assign a label to an image.

5

Use this option to assign a specific label to the6image. Optionally you can include the image filename,4type, width, height, or scene number in the label by:embedding special format characters. Embed %f forJfilename, %m for magick, %w for width, %h for height,N%s for scene number, %b for file size in kilobytes, or \nfor newline. 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.



-matte-
store matte channel if the image has one.



-monochrome+
transform the image to black and white.



-negate#
apply color inversion to image.

8

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

Ž

-page <width>x<height>{+-}<x offset>{+-}<y offset>7
preferred size and location of the Postscript page.

4

Use this option to specify the dimensions of the4Postscript page in pixels per inch or a TEXT page in7pixels. The default for a Postscript page is to center1the image on a letter page 612 by 792 pixels. The5margins are 1/2" (i.e. 612x792+42+42). Other common sizes are:
    Letter      612x 792    Tabloid     792x1224    Ledger     1224x 792    Legal       612x1008    Statement   396x 612    Executive   540x 720    A3          842x1190    A4          595x 842    A5          420x 595    B4          729x1032    B5          516x 729    Folio       612x 936    Quarto      610x 780    10x14       720x1008
:
For convenience you can specify the page size by media(e.g. A4, Ledger, etc.).

5

The page geometry is relative to the vertical and/horizontal density of the Postscript page. See-density for details.

JTo position a GIF image, use -page +LEFT+TOP (e.g. -page +100+200).

<

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

"

-quality value
JPEG quality setting.

:

Quality is 0 (worst) to 100 (best). The default is 75.

-scene value
image scene number.

a

-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).



-stereo5
combine two images into a red-green stereo image.

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.



-tile,
repeat composite operation across image.

$

-treedepth value;
Normally, this integer value is zero or one. A zero or;one tells combine to choose a 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.



-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.


@

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.

@

Change '-' to '+' in any option above to reverse its effect.:For example, specify +matte to store the image without itsmatte channel.

;

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[2,4,7]).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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Environment



DISPLAY8
To get the default host, display number, and screen.



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Copyright

7
Copyright 1997 E. I. du Pont de Nemours and Company:Permission to use, copy, modify, distribute, and sell this8software and its documentation for any purpose is hereby6granted without fee, provided that the above copyright;notice appear in all copies and that both that copyright 6notice and this permission notice appear in supporting4documentation, and that the name of E. I. du Pont de1Nemours and Company not be used in advertising or9publicity pertaining to distribution of the software :without specific, written prior permission. E. I. du Pont9de Nemours and Company makes no representations about the7suitability of this software for any purpose. It is 5provided "as is" without express or implied warranty.

7

E. I. du Pont de Nemours and Company disclaims all 7warranties with regard to this software, including all 8implied warranties of merchantability and fitness, in no:event shall E. I. du Pont de Nemours and Company be liable9for any special, indirect or consequential damages or any6damages whatsoever resulting from loss of use, data or8profits, whether in an action of contract, negligence or6other tortious action, arising out of or in connection-with the use or performance of this software.


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Authors

>
John Cristy, G cristy@sympatico.org E.I. du Pont de Nemours and CompanyIncorporated.


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4[home page]IImage manipulation software that works like magic.