Question

I’m using a UITableView to show 2 to 3 images as thumbnail in each table view cell. The images which I’m showing it in the tableview are huge in size. If I’m using those images directly without any size reduction then the tableview may lose some images if I move back and forth between TableView and other view controllers.

So, I thought of size reduction code which reduces the size of the images. The code given below works great and the previous issue was fixed. But the tableview looses its smooth scrolling because the size reduction code uses a lot of memory. Every time when a new tableview cell is shown, it processes (reduces the size) the images in the particular tableview cell.

There may be a simple solution for this. Thanks in Advance.

//Size Reduction Code

CGSize newSize=CGSizeMake(_new_width, _new_height);
UIGraphicsBeginImageContext( newSize );
[sd._image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
scene_image_preview.image =newImage;

Answer 1

- (void)saveImage:(UIImage *)image withName:(NSString *)name {

            [myArray addObject:name];

        //save image
            NSData *data = UIImageJPEGRepresentation(image, 1.0);
            NSFileManager *fileManager = [NSFileManager defaultManager];
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
            NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:name];
            [fileManager createFileAtPath:fullPath contents:data attributes:nil];

    }

    - (UIImage *)loadImage:(NSString *)name {

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
            NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:name];    
            UIImage *res = [UIImage imageWithContentsOfFile:fullPath];

            return res;
    }

Finally, I got a solution to load number of large sized images simultaneously. First, I reduced the size of the image using the size reduction code above and I saved those sized images to documents directory for the first time and then I loaded the saved images from the documents directory using these saveImage and loadImage functions.

Thanks for all the comments and suggestions to solve this.