w-green shadow. That&rsquo;s because they&rsquo;re doing simple
  bit-shifting (possibly including one round of bit replication), instead of
  proper scaling.</td>
 </tr>

 <tr>
  <td class=q>q/rgba16-4444.bmp</td>
  <td>5</td>
  <td class=b><img src="rgba16-4444.png"></td>
  <td class=b><img src="../q/rgba16-4444.bmp"></td>
  <td>A 16-bit image with an alpha channel. There are 4 bits for each color
   channel, and 4 bits for the alpha channel.
   It&rsquo;s not clear if this is valid, but I can&rsquo;t fin