title: iOS: How to set the proper image scale for a bar button item
body: <p>I'm trying to add my own image as a bar button item, but I don't know how to get the image to scale properly. Apple's Human Interface guidelines recommends that my image be 44x44 px, but when I use a 44x44 px image, it is too large for the toolbar, as you can see:</p>
  
  <p><a href="https://i.stack.imgur.com/7ZrLO.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7ZrLO.png" alt="Example"></a></p>
  
  <p>When I use a smaller version of the image, it looks pixellated on the Retina display. What am I supposed to do here?</p>