title: iOS - View high resolution image
body: <p>I want to display a high resolution image in imageview. Here is what i do</p>
  
  <ol>
  <li>Prepare UIImage in the background</li>
  <li>When the file is loaded, switch to main thread</li>
  <li>Display the image [ by using UIImageView's setImage: ]</li>
  </ol>
  
  <p>The problem is there is a lag in the 3rd step. It takes few seconds and loads the file. And if its a large image, I get the memory warning and a crash. <strong>So is there a way by which i can draw images from top to bottom</strong> ( like how the browser does) ? Also I need to preserve the quality of the image.</p>
  
  <p>Is there a way by which i can achieve my requirement. Thanks in advance</p>