ImageMagick Tricks and Snippets

create a stack of images

e.g. all images named inputimage01.tif .. inputimage99.tif in one folder should be converted to one image-stack

convert -adjoin inputimage*.tif outputimage.tif

“-adjoin” is optional, if outputimage-format can contain multiple images

resize image

- percentage

mogrify -resize 50% image.jpg

- to maximal size (all images in current folder)

mogrify -resize 256x256 *.jpg

- resize and change bit-depth

mogrify -resize 2994x2994 -depth 8 *.tif

shave image

shave off at the image edges to leave away unnecessary parts

mogrify -shave <width>x<height> *.tif

crop image

central crop

mogrify -gravity Center -crop 50x80%+0+0 *

crops image to 50% of width and 80% of height

very small

mogrify -shave 1750x250 -chop 450x0 -crop +0-250 +repage *

modifies image into smaller, cropped image (rescaled for illustration purposes)

"-shave 1750x250"

shaves 1750px left/right and 250 pixel on the top/bottom

"-chop 450x0"

chops off 450 pixel on the left side

"-crop +0-250 +repage"

chops off 250 pixel at the bottom side and repages the canvas of the image.

all info is taken from the IM help

convert

all images in folder from png to jpg

mogrify -format jpg *.png

all images in folder from jpg to eps

mogrify -format eps *.jpg

create a movie out of still images

convert *.jpg movie.mpg

create a listing

to create a listing of the filenames with their size into a textfile use

identify -format "[\"%f\",%w,%h];\n" *.jpg > listing.txt

[via erik krause]

make a montage of a bunch of images

Take a directory full of images and make a nice montage, polaroid-style

montage *.tif -bordercolor yellow -background red \\
+polaroid -gravity center -background none -geometry -50-50 polaroid.png

polaroid.png

Keep in mind that this only works for not very big amounts of not very big images, so “resize” them first. The resulting image is really big, so you might need to resiye that too…

You might also prefer to change the -bordercolor to “white” and the -background to “black”, here it is yellow and red for demonstration purposes…

montage *.tif -thumbnail 256x256 -bordercolor yellow -background red +polaroid \\
-gravity center -background green -geometry +1+1 polaroid-green.png

green background

makes 256×256 -sized thumbnails first and adds a small (1×1) border around each image, so they line up nicely. Substitute “yellow” with “white”, “red” with “black” and “green” with “none” to have a useable result…

adapted from the ImageMagick help