title: Save only a certain part of an HTML canvas
body: <p>Is it possible to save or export only a certain part of the canvas rather than the whole canvas?</p>
  
  <p><a href="http://i.stack.imgur.com/hmvYh.jpg" rel="noreferrer">http://i.stack.imgur.com/hmvYh.jpg</a></p>
  
  <p>At the moment, when I save the file I get the composition plus the transparent background (light blue in example above) of the entire canvas element I have on the site. What I would like to get is only the gray region (which could be made up of several images and text elements).</p>