title: Generating keywords from a pdf automatically
body: <p>My application allows user to upload pdf files and store them on the webserver for later viewing. I store the name of the file, location, size, upload date, user name etc in an SQL server database.</p>
  
  <p>I'd like to be able to programatically, just after a file is uploaded, generate a list of keywords (maybe everything except common words) and store them in the sql database as well so that subsequent users can do keyword searches...</p>
  
  <p>Suggestions on how to approach this task? Does these type of routine already exist?</p>
  
  <p>EDIT: Just to clarify my requirements, I wouldn't be concerned with doing OCR, I don't know the insides' of PDF's, but I understand that if it was generated by an app, such as Word->PDF Print, the text of the document is searchable...so really my first task, and the intent of my question is, how do I access the text of a PDF file from an asp.net app? OCR on scanned PDF's is probably beyond my requirements at this point.</p>