Masking a UIImage with a mask UIImage in iOS

masking-image.m

- (UIImage*) maskImageWithMask:(UIImage *) mask
{
  CGImageRef imageReference = self.CGImage;
  CGImageRef maskReference = mask.CGImage;
  
  CGImageRef imageMask = CGImageMaskCreate(CGImageGetWidth(maskReference),
                                           CGImageGetHeight(maskReference),
                                           CGImageGetBitsPerComponent(maskReference),
                                           CGImageGetBitsPerPixel(maskReference),
                                           CGImageGetBytesPerRow(maskReference),
                                           CGImageGetDataProvider(maskReference),
                                           NULL, // Decode is null
                                           YES // Should interpolate
                                           );
  
  CGImageRef maskedReference = CGImageCreateWithMask(imageReference, imageMask);
  CGImageRelease(imageMask);
  
  UIImage *maskedImage = [UIImage imageWithCGImage:maskedReference];
  CGImageRelease(maskedReference);
  
  return maskedImage;
}

Original was leaking memory