1. Convert your pdf to jpg, using for example the Imagemagick and the following command:
    convert yourpdf.pdf yourpdf.jpg
  2. Create a pdf.xml file in the following format:
     
    <?xml version="1.0" encoding="utf-8" standalone="yes"?>
    <pdf>
    <numImages> 50</numImages>
    <imagePref>your_image_prefix-</imagePref>
    </pdf>
  3. And finally tar all these files together (the images with the pdf.xml)