title: Quartz 2D/OpenGLES geometric distortions on images (preferrably using CGImage)
body: <p>What is the preferred method for implementing such geometric distortions as pinch/fisheye/etc. using the iPhone SDK?  I know that the Core Image library for OSX has all these types of filters built in, but not for the iPhone SDK.</p>
  
  <p>I can create a displacement map at a specific location and radius given the original source bitmap data, but I'm not sure how to apply this bitmap data as a transformation on my CGImage.</p>
  
  <p>This isn't an affine transformation since lines are no longer parallel around the area of distortion/etc.</p>
  
  <p>Is it possible using CGImage or would I need to do this using OpenGLES?</p>
  
  <p>Thanks</p>