// 메타 정보
NSDictionary *metaDic = [NSDictionary dictionaryWithObjectsAndKeys:
                         @"Software", (NSString *)kCGImagePropertyTIFFSoftware,
                         @"Artist", (NSString *)kCGImagePropertyTIFFArtist,
                         @"Description", (NSString *)kCGImagePropertyTIFFImageDescription, nil];
NSDictionary *tiffDic = [NSDictionary dictionaryWithObject:metaDic forKey:(NSString *)kCGImagePropertyTIFFDictionary];
// 이미지
UIImage *image = [UIImage imageNamed:@"sampel.png"];
// 이미지에 메타 정보를 기록하고, 저장
ALAssetsLibrary *library = [[[ALAssetsLibrary alloc] init] autorelease];
[library writeImageToSavedPhotosAlbum:[image CGImage]
                             metadata:tiffDic
                      completionBlock:^(NSURL *newURL, NSError *error) {
                          if (error) {
                              NSLog(@"%@", [error localizedDescription]);
                          } else {
                          }
                      }];