title: Tool to compare large numbers of PDF files?
body: <p>I need to compare large count of PDF files for it optical content. Because the PDF files was created on different platforms and with different versions of the software there are structural differences. For example:</p>
  
  <ul>
  <li>the chunking of text can be different</li>
  <li>the write order can be different</li>
  <li>the position can be differ some pixels</li>
  </ul>
  
  <p>It should compare the content like a human people and not the internal structure. I want test for regressions between different versions of the PDF generator that we used. </p>