title: Read images from a iphone album using ALAssetsLibrary make slow
body: <p>Read images from a iphone album using ALAssetsLibrary will took 30 seconds to load images of 700. Is there any other version of code using  ALAssetsLibrary? My version of Code was below</p>
  
  <pre><code>ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
  [library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
          NSLog(@"number of assets = %ld",(long)group.numberOfAssets);
          [group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
              if(result == nil) {
                  return;
              }
  
              ALAssetRepresentation *representation = [result defaultRepresentation];
  
              BR_AssetsInfo *info = [[BR_AssetsInfo alloc] init];
              info.thumbnail = [UIImage imageWithCGImage:[result thumbnail]];
              info.originalImage = [UIImage imageWithCGImage:[representation fullResolutionImage]];
              info.imageURLString = [[representation url] absoluteString];
              info.isSelected = NO;
  
              for (BR_AssetsInfo *asset in self.selectedAssetsArray) {
                  if ([asset isEqual:info]) {
                      info.isSelected = YES;
                  }
              }
  
              [self.assetsDataArray addObject:info];
  
              [self.photosCollectionView reloadData];
  
          }];
      } failureBlock:^(NSError *error) {
          if (error.code == ALAssetsLibraryAccessUserDeniedError) {
              NSLog(@"user denied access, code: %li",(long)error.code);
          }else{
              NSLog(@"Other error code: %li",(long)error.code);
          }
      }];
  </code></pre>