滚动后删除UICollectionView中的ImageView修改

Question

在我的collectionView中，我有一幅具有白色背景的图像，我使用KCG混合模式制作了另一幅图像，并将其添加为覆盖以使背景变为灰色。问题是，当我滚动查看新图像或滚动浏览以查看旧图像时，图像会重置为原始图像。

我相信这是由于dequeueReusableCell造成的：

 -(UICollectionViewCell *)collectionView:(UICollectionView 
*)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
Product *product = [self.products content][indexPath.row];
ProductCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kGENERIC_COLLECTION_CELL_ID forIndexPath:indexPath];

//set image
NSString *imageUrlString = [NSString stringWithFormat:@"%@%@", [product image_thumb_path], [product image_thumb]]; //create url using path & image
[cell.imageView sd_setImageWithURL:[NSURL URLWithString:imageUrlString]
                  placeholderImage:nil
                         completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
                             if (cacheType != SDImageCacheTypeMemory)
                             {
                                // cell.imageView.alpha = 0.0;
                                 double val = ((double)arc4random()/ARC4RANDOM_MAX)*0.8;
                                 [UIView animateWithDuration:0.2 delay:val options:UIViewAnimationOptionCurveEaseInOut animations:^{

                                     UIImage *backgroundImage = [UIImage imageNamed:@"grey.jpeg"];
                                     CGFloat width = 100;
                                     CGFloat height = 100;
                                     CGSize size = CGSizeMake(width, height);

                                     UIGraphicsBeginImageContext(size);
                                     CGRect areaSize = CGRectMake(0, 0, size.width, size.height);
                                     [backgroundImage drawInRect:areaSize];
                                     [image drawInRect:areaSize blendMode:kCGBlendModeMultiply alpha:2.8];
                                     UIImage *mainImage = UIGraphicsGetImageFromCurrentImageContext();
                                     UIGraphicsEndImageContext();

                                    cell.imageView.image = mainImage;

                               //     cell.imageView.image = [cell.imageView.image         imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
                               //    cell.imageView.tintColor = UIColor.grayColor;

                                // cell.imageView.image = [cell.imageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
                                 } completion:nil];
                             }
                         }];
}

什么是避免遇到此问题的最佳方法？