title: Convolving an image with OpenGL ES on iPhone: possible?
body: <p>I've googled around a few times, but I have not gotten a straight answer.  I have a matrix that I would like to convolve with a discrete filter (e.g. the Sobel operator for edge detection).  Is it possible to do this in an accelerated way with OpenGL ES on the iPhone?</p>
  
  <p>If it is, how how?  If it is not, are there other high-performance tricks I can use to speed up the operation?  Wizardly ARM assembly operations that can do it fast?  Ultimately I want to perform as fast of a convolution as possible on an iPhone's ARM processor.</p>