title: convert multiple pngs to bmps from stdin to stdout
body: <p>I need to to <strong>convert PNGs coming from chrome-headless to BMPs</strong> to work with them, and I also need to do this <strong>through pipes</strong> without saving those images somewhere.</p>
  
  <p>Chrome is set up to just screencast the images to stdout, which is working fine, but I can't seem to get the imagemagick convert tool to do, what I need.</p>
  
  <p>While testing with</p>
  
  <pre><code>cat foo.png | convert PNG:- BMP:-
  </code></pre>
  
  <p>seems to work with one input image (Output starts with 'BM', indicating BMP binary garbage),</p>
  
  <pre><code>cat foo.png bar.png | convert PNG:- BMP:-
  </code></pre>
  
  <p>also returns only one image, which seems to be the first one.</p>
  
  <p><strong>How can I get convert to "overwrite" the output for each file it reads through stdin?</strong></p>
  
  <hr>
  
  <p>EDIT: The cat example is just to demonstrate the input. The final idea is more like</p>
  
  <pre><code>chrome-headless | *solution* | bmpreader
  </code></pre>
  
  <p>As fmw42 and Mark pointed out, this doesn't seem to be possible with imagemagick out of the box.</p>