이미지 두개 합치기

UIImage* ImageMerge(UIImage* firstImage, UIImage* secondImage){ 
    UIGraphicsBeginImageContext(firstImage.size); 
    [firstImage drawAtPoint:CGPointMake(0,0)];
    [secondImage drawAtPoint:CGPointMake(0,0)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 
    return newImage; 
}