title: How to detect a large image in PDF and extract it as a JPEG or any format?
body: <p>I'm creating a project that creates a magazine from PDF file, however each uploaded magazine should have a thump that has a cover photo, and i want to extract this image from the PDF as a JPEG in order to set it as a cover photo. </p>
  
  <p>Is there any way to do it using Ghostscript or any other command line tool ?</p>