使用Objective C将位图转换为PNG或JPG

Question

任何人都知道如何使用Objective C将位图转换为PNG或JPG，假设我有

CGImageRef imageRef;

Answer 1

UIImage *myImage = [UIImage imageWithCGImage:imageRef];
NSData *pngData = UIImagePNGRepresentation(myImage);
NSData *jpgData = UIImageJPEGRepresentation(myImage);