title: Preventing crash after imagePickerController:didFinishPickingMediaWithInfo
body: <p>I am working on an image filter effects app.</p>
  
  <p>A current issue with the app is that it crashes when a user picks a very large image from his photo album.</p>
  
  <p>When</p>
  
  <pre><code>imagePickerController:didFinishPickingMediaWithInfo
  </code></pre>
  
  <p>returns the selected image, I need to present a preview of the selected image in a UIImageView.</p>
  
  <p>I resize the selected image if it's large before presenting it.</p>
  
  <p>For very large images (20 megapixels +) this causes the app to crash - I am not getting any memory warnings before the crash that I can act on.</p>
  
  <p>I would like to prevent a crash, or at least warn the user that this might happen if they select a very large image.</p>
  
  <p>Does anyone have a good idea how to implement this (crash prevention or warning) gracefully?</p>