title: How to convert .pdf to .png
body: <p>Using ImageMagick I can convert any pdf document into images by using command "convert":</p>
  
  <pre><code>convert abc.pdf abc.png
  </code></pre>
  
  <p>This will convert all pdf pages to png images.</p>
  
  <p>How can I implement this using PHP or Java so that I can provide this functionality on my website to enable users to read books online as Google Books does.</p>