title: Using convert or mogrify to merge multiple PNG files into a single multi-page TIFF file
body: <p>Say I have a folder <code>foo</code> with multiple PNG files. Is there a way to use <code>convert</code> or <code>mogrify</code> to merge the PNG files into a single TIFF file?</p>
  
  <p>I have tried:</p>
  
  <pre><code>mogrify -format tiff -adjoin *.png
  </code></pre>
  
  <p>but I get <code>unrecognized option -adjoin</code></p>