Need help using UIImagePNGRepresentation
<p>I'm trying to save a UIImageView image to a png file, and then use that file as a GLTexture.
I'm having trouble with this, when I try to run my code in the simulator, XCode says it succeeded, but the simulator crashes with no error messages.  Can someone help me with this?
Here is my code:</p>

<pre><code>NSString *dataFilePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Picture.png"];

  NSData *imageData = UIImagePNGRepresentation(imageView.image);
  [imageData writeToFile:dataFilePath atomically:YES];

  // Load image into texture
  loadTexture("Picture.png", &amp;Input, &amp;renderer);
</code></pre>
