[Corpora-List] pdfs/ OCR question

Alexandre Rafalovitch arafalov at gmail.com
Mon Dec 11 17:23:00 CET 2006

I would guess that the OCR had been done by the software that
generated the PDF. You might be able to check what it is by looking at
PDF document's properties. The text is stored on a separate layer from
the image and the reader just does region matching for the selection

If you need to have this fixed, you probably will need to burst out
the PDF into its page images and have those re-OCRed.

Software you might find useful include PDFBox (http://www.pdfbox.org/)
and Gamera (http://ldp.library.jhu.edu/projects/gamera/)

You can also look at the Distributed Proofreaders to see if there is
anything to be learned from their experience: http://www.pgdp.net/


On 12/11/06, Hunter, Duncan <D.I.Hunter at warwick.ac.uk> wrote:

> Quick question about pdfs/ OCR:


> Some text is copied and from a pdf file and pasted into a text or Word file.

> It contains errors- say, for example, 'the' has become 'die' (you notice

> that in the original pdf the 't' and 'h' are quite close together). At what

> stage has this misrecognition/ miscopying occured?

> Where does the OCR take place? The OCR functionality is, presumably, part

> of of the .pdf reader software itself?


> Can anything be done to deal with the problem?


> Duncan Hunter



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