title: Does UIImage(contentsOfFile: <String>) take into consideration screen scale?
body: <p>I have an image on disk and load it like so:</p>
  
  <pre><code>guard let image = UIImage(contentsOfFile: url.path!) else { return }
  self.testImageView.image = image
  </code></pre>
  
  <p>When loading an image like this form file, will the image be drawn on screen with the correct scale factor?</p>
  
  <p>I am asking because when I do this:</p>
  
  <pre><code>guard let imageData = NSData(contentsOfFile: url.path!) else { return }            
  guard let image = UIImage(data: imageData, scale: UIScreen.mainScreen().scale) else { return }
  self.testImageView.image = image
  </code></pre>
  
  <p>the image looks way sharper.</p>