Linux Tips & Tricks - image processing from the command line
The first time you have to process a lot of images in the same way or need to process them from a script, you'll be thrilled to learn about the wealth of command line tools available. Here is a small sampling of those tools to get you started.
https://opensource.com/life/16/9/command-line-image-tools-linux
I use convert a lot
ReplyDeletelinux.die.net - convert(1) - Linux man page