java - Check if a PDF file is a scanned one

Question

What is the best way to programmatically check if a PDF file is a totally scanned one? I do have iText and PDFBox at my disposal. I can check if a pdf file contains text or not, and according to the result to decide if this file is OCRed, but this solution is not 100% accurate. I'd like to know whether there is another way to cope with the problem.

As you understand the solution must be Java based.

Answer 1

Your best bet might be to check to see if it has text and also see if it contains a large pagesized image or lots of tiled images which cover the page. If you also check the metadata this should cover most options.