Investigating OCR

July 6, 2007

Hi,

Since 0.5.1, i’m investigating OCR for Gnome through Gnome Scan. The most advanced software is OCRopus. OCRopus is to tesseract what HTML is to plain/text. And in fact, OCRopus output HTML :). OCRopus is currently based on the famous tesseract OCR engin, but some hocr code is in the repo, and more is to come.

Just like Gegl, i ensure that even alpha softwares i use in gnome-scan are at least packaged, either in an official repos or by my own. Tesseract is packaged, but OCRopus require tesseract SVN which does not built and has a bug (public headers includes config.h). The built failure received a patch waiting for inclusion, and i provide a patch fixing the last issue.

The main issue is that OCRopus has never publish a release. It has only SVN repo. OCRopus uses Jam without any rules to generate a distribution package (like make distcheck from automake). After some research, i decided to add automake build system to OCRopus. Tesseract has two build system : one for developer, one for distributor. Automake is still the best solution for distributor.

I provided a quite big but incomplete patch at OCRopus mailing list which received some attention. It seems that tesseract and OCRopus are very close together. Both are not very active. I hope that gnome-scan will tick those project developers and put them to users. OCRopus has only a command line tool, it should provide a library. Tesseract provide 11 libraries, it should provide only one !

So, gnome-scan OCR is kind of blocked by upstream project that’s needs some love. Both projects needs to modify a bit their design. I think i will provide a “protocropus” plugin for gnome-scan which will provide a simple bridge between the various command line OCR tools or libraries (including OCRopus), but not depending on OCRopus.

√Čtienne.

2 Responses to “Investigating OCR”

  1. Anonymous Says:

    Many projects is moving away from automake for something usable.

    Dont do the reverse. Some example: scribus, inkscape (on windows at least, but there are continuous discussion to moving away from automake, because nobody really familiar withit, and requires some magic.

    Automake is like cvs, definietly need a replace like cvs to svn, git, etc.

    What about cmake?

  2. Bronzecat Says:

    ctky searching for an OCR software for Linux and more precisely gnome, finding such professional software is often pure luck!
    Please keep working on it, it’s a great piece of professional software that, I am totally certain, many people need.


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