title: Loss of quality passing images from viewcontroller iOS
body: <p>i'm developing an application that allows users to add masks at their photos, the app works well but i noticed a problem, i don't know why but the image loses quality.
  i'm passing images to view controllers by using this method:</p>
  
  <pre><code>   AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
  
  //SETTO STICKERS
  UIGraphicsBeginImageContext(CGSizeMake(_Image.frame.size.width, _Image.frame.size.height));
  CGContextRef context = UIGraphicsGetCurrentContext();
  [_Image.layer renderInContext:context];
  UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  
  appDelegate.ImageEnded = screenShot;
  //Instanzio il viewController della main
  LastViewController *VC = [self.storyboard instantiateViewControllerWithIdentifier:@"LastVC"];
  //Vado alla main
  [self presentModalViewController:VC animated:YES];
  </code></pre>
  
  <p>and by take the image from the other ViewController using the appdelegate, here is my full app-process:</p>
  
  <blockquote>
    <p>FirstScreen(ViewController) ->  TakePhoto or Select from gallery -><br>
    AddMask(ViewController) -> AddStickers(ViewController) ->
    LastViewcontroller(ViewController) .</p>
  </blockquote>