Command line: ImageMagick

The swiss army knife for picture manipulation in the command line. For future reference, this mainly use v7 which has Git-style interface (which is way better, IMO).

Synopsis

magick [subcommand [subcommand_options...]]

Subcommands

• convert - resize images, convert between formats, apply filter effects

• identify - print information on the image

• mogrify - similar to convert except modifies the original file

Examples

A comprehensive tool calls for a comprehensive introduction.

Resize an image by half

magick resize $INPUT -resize 50% $OUTPUT

You can find out various geometry options from the documentation.

Print the information

magick identify $INPUT

Use ImageMagick as a color picker

You can use any tool that can pipe an image to other tools.

maim --select --shader crosshair --tolerance 0 --hidecursor | magick convert - -resize 1x1\! -format '%[hex:p{0,0}]' info:-