| author | title | date |
|---|---|---|
Giovanni Cangiani <<giovanni.cangiani@epfl.ch>> |
— EPFL Dojo — \ ImageMagick |
2020-06-25 |
https://imagemagick.org | https://github.com/imagemagick/imagemagick
ImageMagick is a free and open-source software suite for displaying, creating, converting, modifying, and editing raster images. It can read and write over 200 image file formats.
https://en.wikipedia.org/wiki/ImageMagick
ImageMagick was created in 1987 by John Cristy when working at DuPont, to convert 24-bit images (16 million colors) to 8-bit images (256 colors), so they could be displayed on most screens. It was freely released in 1990 when DuPont agreed to transfer copyright to ImageMagick Studio LLC, still currently the project maintainer organization.
https://en.wikipedia.org/wiki/ImageMagick#History
- File format conversion
- Animation
- Color management
- Command-line processing
- Montage
- Special effects
- Text & comments
- and much more...
% identify [-verbose] MM.jpg
MM.jpg JPEG 300x450 300x450+0+0 8-bit sRGB 129840B 0.000u 0:00.000
https://imagemagick.org/script/identify.php
convert original.jpg -quality 10 compressed.jpg
convert MM.jpg -gravity North -crop 200x200 +repage MM_square.jpg
https://imagemagick.org/Usage/crop/
convert MM.jpg -resize 50% MM_halfsize.jpg
convert MM.jpg -resize "400x" MM_400stupid.jpg
convert MM.jpg -resize "400x>" MM_400clever.jpg
identify MM_400clever.jpg
> MM_600clever.jpg JPEG 300x450 300x450+0+0 8-bit sRGB 120472B 0.000u 0:00.000
https://imagemagick.org/Usage/resize/
halfsize / stupid / clever
convert MM_square.jpg -clone 0 -clone 0 \( -clone 0 -channel RGB -negate \) \
miff:- | montage - -geometry +0+0 MM_multiple.jpg
https://imagemagick.org/Usage/montage/
convert MM_square.jpg -colorspace gray MM_square_gray.jpg
https://imagemagick.org/www/script/color-management.php
+ 
composite -gravity south dojoman.png CB.jpg CB_com.jpg
composite -watermark 30x100 -gravity south dojoman.png CB.jpg CB_com.jpg
composite -watermark 30x0 -gravity south dojoman.png CB.jpg CB_com.jpg
convert -background transparent -fill "#ffffff" \
-font Helvetica -pointsize 240 label:"(C) EPFL-Dojo" miff:- \
| composite -watermark 30x100 -gravity SouthEast - CB.jpg CB_wm3.jpg
scale% | scale-x%xscale-y%: H and W scaled by specified percentage.width | xheight: W or H given, keep ARwidthxheight: max W or H, keep ARwidthxheight^: min W or H, keep ARwidthxheight!: exact W and H, AR ignoredwidthxheight>: shrink if larger.widthxheight<: enlarge if smallerarea@: total number of pixels, keep AR
{size}{+-}x{+-}y
- Specifying the offset (default is
+0+0). - Affected by
-gravity - Sign matters!
https://imagemagick.org/script/command-line-processing.php#geometry
-region geometry can be used to change portion of the image:
convert MM.jpg -region 134x70+240+524 -modulate 100,100,50 MM_relip.jpg
options with + and - have differen mening. Example:
-writewrites the image in the given format. The image will be available for further processing later in the pipe+writewrites the image in the given format but duplicate the original before so that the next processing in the pipe is done on an uncompressed image-appendattach image below+appendattach image on the right
- is the internal IM storage and can hold several images
- is normally used to pass set of images between IM commands
- identify (
identify [-verbose] file.pngis equivalent toconvert [-verbose] file.png info:-) - convert (magick)
- compare
- composite
- mogrify
- montage
- display (X11 only)
% convert -list interpolate
Average
Average4
Average9
Average16
Background
Bilinear
Blend
Catrom
Integer
Mesh
Nearest
Spline