title: UIImage memory usage with png and jpg
body: <p>I have two files in the Documents directory of the same image taken with the camera. One was saved using UIImagePNGRepresentation and the the other one using UIImageJPEGRepresentation. In other word, one is a png and the other is a jpg.</p>
  
  <p>Now, using the the instrument with a real device. if I load the png (initWithContentOfFile:), the 'Real memory' goes from 2.34 MB to 2.43 MB. But if I load the jpeg instead, the memory goes from 2.34 MB to over 23 MB!!! I had similar results loading any png versus jpeg.</p>
  
  <p>Can somebody can help me understand why?</p>