I use this script for taking screenshots, bound to the Print Scrn key with i3wm. It dumps a screenshot into my 'Pictures' directory, and makes a beep. You can set it to make a notification if you want.

screenshot.sh

#!/bin/bash
import -window root $HOME/Pictures/screenshot_`date +%y-%m-%d_%H-%M-%S`.png

• Graphics from the command line - Archive of 2003 guide by Michael Still.
• More graphics from the command line - Archive of 2004 guide by Michael Still.
• Examples of ImageMagick Usage (Legacy Version 6)
  • §Separating Spaced-out Tiling Images
  • §Cropping into roughly Equally Sized Divisions
  • sprite sheets to animated .gif files - forum thread.
• Convert sprite sheet to gif animation - Stackoverflow, 2019.
• Fred's ImageMagick Scripts

• imagemagick.org
• imagemagick/imagemagick
• ImageMagick
• ImageMagick