title: What's the most efficient way to combine the image tiles from xckd's Click and Drag into a single composite .png?
body: <p>I'm attempting to combine all of the image tiles from <a href="http://xckd.com/1110/" rel="nofollow">Click and Drag</a> using ImageMagick.  It's taking a considerably long time to process.</p>
  
  <p>More generally, if I have collection of greyscale, 8-bit png files that I want to combine (tile) into a single image, what would be the most efficient settings?  </p>
  
  <p>So far the strategy I've come up with is</p>
  
  <ul>
  <li>Use <code>convert</code> with <code>+append</code> and <code>-append</code></li>
  <li>Use the Q8 (8-bit color) version</li>
  </ul>
  
  <p>Are there other png settings I should consider?  Maybe us uncompressed intermediate files?</p>