imagemagick

Some sample image commands

get image file information

• magick identify image.tif

convert from tiff to jpeg

• magick image.tif image.jpg
• magick -quality 80 image.tif image.jpg

scale image

• magick image.tif -scale 50% image.jpg

make grayscale

• magick image.tif -type Grayscale image.jpg

resize image

• magick image.tif -resize 1000 image.png
• magick image.tif -resize x1000 image.png

crop image

• magick image.jpg -crop 800x800+1000+1000 crop.jpg

scale and crop image

• magick image.jpg -scale 25% -crop 300x300+500+500 crop.jpg

modify brightness, saturation, hue

• magick old.jpg -modulate 150,100,100 new.jpg

The above command increases brightness 150%. To decrease brightness, use values less than 100.

The 3 numbers represent: brightness, saturation, and hue. They are all interpreted as percentages.

add border

• magick image.png -bordercolor red -border 1 border.png

Lab

1. Download sample image file: https://jawalsh.luddy.indiana.edu/teaching/z652/sample_images.zip
2. Run some imagemagick commands to convert your tiff files to 3 different sizes of jpg files:
   • a “large” file that is 1000 pixels long on its longest side
   • a “medium” file that 500 pixels long on its longest side
   • a “thumbnail” file that is 200 pixels long on its longest side
3. Use imagemagick to rotate the rotate_left.tiff and rotate_right.tiff images.
4. Use imagemagick to crop the comics.tif images so you have an image file with just the title panel:
   • 
5. Spend a few minutes experimenting with the commands above, then review the documentation at https://www.imagemagick.org/script/command-line-processing.php and https://www.imagemagick.org/script/command-line-tools.php and explore some commands on your own. You might also try searching the internet for things like “imagemagick watermark” for instructions on how to use imagemagick to put a watermark on your images. Or try one of these short tutorials:
   • Another list of ImageMagick commands
   • https://www.linuxjournal.com/content/easy-watermarking-imagemagick
   • https://www.brianlinkletter.com/process-images-for-your-blog-with-imagemagick/