most used imageMagick commands

the following commands are the most common ImageMagick commands i use. when i used windows 11 i needed to add magick first (so for example magick mogrify -format jpg image.png) for the commands to work but i can use commands like mogrify, convert, etc directly in linux.

compression

i compress images so pages load faster and my site stays within the 1gb limit. the most common command i use is

mogrify -resize 800> -format jpg -quality 80 -strip *.heic

which i use for images on my microblog. my images usually end up a tenth of their original size. strip removes metadata such as the location where photos were taken. replace heic with the formats of the image you want to convert. if i find the result to be too low quality i use

for file in *.heic; do magick "$file" +sigmoidal-contrast 6.5,50% -filter Lanczos -distort Resize x800\> -unsharp 0.75x0.75+0.5+0.02 -sigmoidal-contrast 6.5,50% -format jpg -quality 90 -strip "${file%.*}.jpg"; done

which is much slower but adds a bit of sharpening and helps to preserve the depth of color. if i want to add some dithering i use

mogrify -resize 800x -unsharp 1.25x1.25+0.5+0.02 -dither FloydSteinberg -colors 128 -depth 10 -format jpg -quality 90 *.png

which adds a bit of sharpening before dithering using the floyd steinberg algorithm.

extract first frame of a gif

within a folder, the following command

mogrify -format png "*.gif[0]"

extracts the first frame of every gif in the folder and writes it to a png which uses the same file name.