title: How to load images from an NSURL with the imageNamed behaviour (@2x, ~ipad etc. variants)
body: <p><code>[UIImage imageNamed:]</code> will do lots of clever things when loading files from the bundle, like caching to prevent multiple <code>UIImage</code> instances of the same image, looking for @2x and ~ipad suffixes, and setting the <code>scale</code> property correctly. I want to be able to do the same thing when loading images from the documents directory (specified with a <code>NSURL</code>). I've looked around but can't find anything in the docs for this, is there something I've missed?</p>
  
  <p>I'm currently implementing this myself (the whole shebang, with caching, etc.) but I hate to duplicate framework code. I hope to get an answer before I'm done but if not I'll post the code.</p>