HOW TO: Shrink (Gparted) an Image (IMG) in Linux
This tutorial will help you shrink ANY image file you have with gparted on Linux. Have you ever tried to backup your SD card onto an image file and shared it to someone else? You probably heard that they weren’t able to burn it to the SD because it’s too big. You can reduce the file size by shrinking the size of your image.
Thanks to Emul.ga for this guide