title: Detect which image is sharper
body: <p>I'm looking for a way to detect which of two (similar) images is sharper.</p>
  
  <p>I'm thinking this could be using some measure of overall sharpness and generating a score (hypothetical example: image1 has sharpness score of 9, image2 has sharpness score of 7; so image1 is sharper)</p>
  
  <p>I've done some searches for sharpness detection/scoring algorithms, but have only come across ones that will enhance image sharpness.</p>
  
  <p>Has anyone done something like this, or have any useful resources/leads?</p>
  
  <p>I would be using this functionality in the context of a webapp, so PHP or C/C++ is preferred.</p>