Compares two image files and returns the PSNR and MSE values.

psnr_check.sh

#!/bin/bash

if [ -e "$1" ] && [ -e "$2"  ];
then
  if file "$1" | grep -qE 'image|bitmap' && file "$2" | grep -qE 'image|bitmap' ;
  then
    ffmpeg -loglevel error -i "$1" -i "$2" -lavfi psnr=psnr.log -f null -
    cat psnr.log
    rm psnr.log
  else
    echo "The first and/or the second file isn't a valid image file!"
    exit 0
  fi
else
  echo "The first and/or the second file doesn't exist! Please make sure to run the command: './psnr_check.sh path/to/reference/file path/to/processed/file'"
  exit 0
fi