I have a UIImageView that I want to manipulate within the touchesMoved method that smudges pixels around the UITouch passed in the set. I want it to act like the smudge tool in Photoshop and be fast. (I do know that even the hotoshop one is a little laggy but I want it to be as fast as possible) I have almost no knowledge of CGContext or Open GL but if you can convince me which one will be better then I will learn it. If you know of a source that would teach me how to do this or learn CGContext or Open GL (If I need one of those) the please let me know of it.