title: create hash from image contents with PHP?
body: <p>I currently create a hash from an image name but would rather create a hash based on the contents of an image so I can detect duplicate images.  Are their any PHP classes that do this?</p>
  
  <p>My current code is very simple:</p>
  
  <pre><code>$image = "image1.jpg"; 
  $filehash = md5_file($image );
  </code></pre>