title: function to duplicate images for thumbnail?
body: <p>I'm making a photo gallery app.</p>
  
  <p>I'm compressing the images</p>
  
  <pre><code>NSData *imageData = UIImageJPEGRepresentation(image,0.5)
  </code></pre>
  
  <p>and then want to create a duplicate (for thumbnails) that I'll compress even further</p>
  
  <pre><code>NSData *imageData = UIImageJPEGRepresentation(image,0.2)
  </code></pre>
  
  <p>I'm a little stuck on the middle step of how to create a duplicate, anyone know if there is a function for this?</p>