title: An easy way (tool?) to compare images pixel for pixel in different formats?
body: <p>Well I've written a basic lossless jpeg joiner thing in java now but I'd like to compare the files it produces with the original files.</p>
  
  <p>I can only compare so much in a hex editor, does anyone know of an easy way, software or java based (preferably software as I dont feel like any more coding for now!) that I can compare two images and produce a "difference map" of where the pixels aren't the same?</p>
  
  <p>Thanks.</p>