How to save image in photo album?

I am using GLImageProcessing sample code.I want to save modified image in phot开发者_运维知识库o album how it possible.please help me.

See this answer to this question for how to use glReadPixels() to extract the image from OpenGL ES within a CAEAGLLayer into a UIImage that you can store in the photos library using UIImageWriteToSavedPhotosAlbum(). The standard approach of using -renderInContext: to generate a UIImage from a CALayer does not work for OpenGL ES content.