title: comparing images programmatically - lib or class
body: <p>My objective is to supply 2 image files, and get a true/false response as to whether these 2 files could be the same (within an acceptable degree of certainty). </p>
  
  <p>I realize this question falls under artificial intelligence and is much more complex than it appears, so I highly doubt I could (or would even want to) do it myself. What I'm looking for is probably a library or a class. I'm working with PHP. </p>
  
  <p>thanks in advance.. </p>
  
  <p>All helpful answers/comments get up voted..</p>
  
  <p><strong>Update:</strong></p>
  
  <p><strong>I wonder if I'm over-complicating it, and maybe a more general library like imageMagick (imagick) could get it done? Anyone who's more experienced with imageMagick?</strong></p>