I want a screenshot of the image on the screen saved into the saved photo library.
Below method works for OPENGL objects also
//iOS7 or above
- (UIImage *) screenshot {
CGSize size = CGSizeMake(your_width, your_height);
UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);
CGRect rec = CGRectMake(0, 0, your_width, your_height);
[_viewController.view drawViewHierarchyInRect:rec afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}