You would need to do something like this. I am typing this off the top of my head, so this may not be 100% correct.
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, 640, 360, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst); CGColorSpaceRelease(colorSpace); CGContextDrawImage(context, CGRectMake(0,-160,640,360), cgImgFromAVCaptureSession); CGImageRef image = CGBitmapContextCreateImage(context); UIImage* myCroppedImg = [UIImage imageWithCGImage:image]; CGContextRelease(context);