Segment a CGImage

In iOS 4.0 and later is there a way to segment a CGImage without loading the entire image into memory? What I am attempting to do is * programmatically* segment an image for use in a CATil开发者_高级运维edLayer application using large images, but I don't want to take up the memory involved in loading the full image.

Also, is there a way to load that (or any) segment at a particular resolution, so if we are zoomed out from the image we can load that tile at a low level of detail, thus saving memory.

Thanks! -Matt

You'll have to load the whole image in memory in order to segment it. If you're interested I can give you some code to do so.