title: Pipe stream to graphicsmagick/imagemagick child process
body: <p>I am trying to pipe data from a stream into a child process.</p>
  
  <pre><code>var gm = spawn( 'gm convert - -thumbnail 220x165^ -gravity center -extent 220x165 thumb.jpg' );
  var rs = fs.createReadStream( 'cow.jpg' );
  
  rs.pipe( gm.stdin )
  </code></pre>
  
  <p>Do I need to call end on gm for it to work? Also in my real code I am getting the stream from a database.</p>