title: How to modify an image before caching it with HJCache?
body: <p>I've been using HJCache to do asynch image loading and caching. It works great, but I have use case where I can't seem to get HJCache to handle.</p>
  
  <p>I have an images loaded in a table view, and the same images appears bigger when you select the corresponding tableviewcell. HJCache does a great job of caching the image so it doesn't have to reload it after getting it once. However, I would like to resize the image (and do some cropping, etc) in the tableview thumbnail. The problem is, that it's a very expensive task to do and it ends up lagging the scrolling of the tableview if it's done in the drawRect of the cell.</p>
  
  <p>I would like to cache the "modified" image along with the original so that the image processing only has to happen once. How do i get an instance of the already cached UIImage, apply the processing, and then add that one to the cache as well (with a different oid). I only seem to be able to cache an image by giving a URL.</p>
  
  <p>Thank you,
  Matt</p>