title: PDF toUnicode cmap table restore
body: <p>I have multiple pdf files without 'toUnicode' cmap table. Absence of cmap table restricts me from copying the text from pdf files. </p>
  
  <p>As far as I know, there is a possibility to add 'toUnicode' mapping in pdf file, but in my case adding static values is not an option, different files have different glyph codes. </p>
  
  <p>So the question is the following. Is there any possibility to restore 'toUnicode' cmap table, perhaps with the help of Ghostscript, or are there any options at all? </p>
  
  <p>Thanks.</p>