Your image size is whats causing your memory issues in your collection view and choppy scrolling. Resize your image, add the re sized image to your collection view
//resize image
CGSize destinationSize = CGSizeMake(264,476);
UIGraphicsBeginImageContext(destinationSize);
[image drawInRect:CGRectMake(0,0,destinationSize.width, destinationSize.height)];
//New image
UIImage*newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//Optimise image
NSData *imageDataCompressed = UIImageJPEGRepresentation(newImage, 0.4f);
NSLog(@"Image Size %@", NSStringFromCGSize(newImage.size));//log size of image