Install findimagedupes by entering the following commands in the terminal:
sudo apt update sudo apt install findimagedupes
Description:
Finds visually similar or duplicate images
findimagedupes is a commandline utility which performs a rough "visual diff" to two images. This allows you to compare two images or a whole tree of images and determine if any are similar or identical. On common image types, findimagedupes seems to be around 98% accurate.
Homepage: http://www.jhnc.org/findimagedupes/
Version: 2.18-6build4
Section: universe/graphics