Linux

Couldnt you just put a custom script onto the print button to take the screenshot and send it to a light editing program?
I have my normal screenshot button and another one which afterwards send the selected region to img2txt and puts the detected text into the clipboard.

I had a good think about how to do this The Unix Way™ and my best sugestion would be to have a script that monitors a folder for screenshots and launches a program (gimp) when it sees something. I wrote one, tried it out, and it works really well!

For this, I used inotifywait which you can get by installing inotify-tools (at least, that's what it's called in Arch):

#!/bin/bash

inotifywait -m "${HOME}/Pictures/Screenshots/" -e create -e moved_to |
    while read -r directory action file; do
        if [[ "${file}" =~ ^Screenshot.* ]]; then
            gimp "${file}"
        fi
    done

All this does is use inotify to trigger an action whenever a file is created in the folder (in this case, the Screenshots folder in ${HOME}/Pictures). For our purposes, it just looks for files named Screenshot<something> and if one appears, we launch gimp.

The result is that if you run this thing and start screenshotting with GNOME's built-in tool, each action will trigger gimp. You can then further expand this to perform some sort of custom action (either with a gimp macro or with some Python script, whatever) so that whenever you're running this script, it'll take that screenshot and do something to it whenever it's created.

Does this help?