title: Processing still image in realtime using GPUImage
body: <p>Is it possible to process still image that is visible in view's content only without making processed UIImage copy of it? For example I have 8 megapixel image in fullscreen view pinched to actual pixels, I want to process only what's on the screen. Basically I want a "viewport" that processes it's content (image in most cases) in real-time.</p>
  
  <p>Thanks,
  Toto</p>