Compare two images and return whether or not they match

compareImages.sh

#!/bin/bash

THRESHOLD="15000" # You'll need to do some testing to come up with this number.

# Requires ImageMagick, also using PNG format since JPEG adds too much noise
echo "`compare -metric RMSE clean_webcam_image.png corrupt_webcam_image.png NULL: 2>&1 | awk '{print $1}'` > ${THRESHOLD}" | bc # Returns 1 if the difference is greater than 15000, 0 otherwise