title: importing python modules - ImageChops
body: <p>I'm looking for a good way to analyze image similarity, using python.
  I'm NOT looking for a way to establish whether two images are identical. I'm just looking for a way to establish the similarity between two images (e.g., if two images are very similar they could be given a "grade" of 9/10; if they are completely unalike, they'll be given a very low index, such as 2/10).
  From some reading that I've done, the module ImageChops has been suggested - however, I haven't been able to find a way to download it. 
  If anyone knows how to download it, or has a suggestion for other effective solutions, I'd greatly appreciate their advice!</p>
  
  <p>Thanks in advance!</p>