NAME

       unicharset_extractor - extract unicharset from Tesseract boxfiles

SYNOPSIS

       unicharset_extractor [-D dir] FILE...

DESCRIPTION

       Tesseract needs to know the set of possible characters it can output. To generate the
       unicharset data file, use the unicharset_extractor program on the same training pages
       bounding box files as used for clustering:

           unicharset_extractor fontfile_1.box fontfile_2.box ...

       The unicharset will be put into the file dir/unicharset, or simply ./unicharset if no
       output directory is provided.

       Tesseract also needs to have access to character properties isalpha, isdigit, isupper,
       islower, ispunctuation. all of this auxilury data and more is encoded in this file. (See
       unicharset(5))

       If your system supports the wctype functions, these values will be set automatically by
       unicharset_extractor and there is no need to edit the unicharset file. On some older
       systems (eg Windows 95), the unicharset file must be edited by hand to add these property
       description codes.

       NOTE The unicharset file must be regenerated whenever inttemp, normproto and pffmtable are
       generated (i.e. they must all be recreated when the box file is changed) as they have to
       be in sync. This is made easier than in previous versions by running unicharset_extractor
       before mftraining and cntraining, and giving the unicharset to mftraining.

SEE ALSO

       tesseract(1), unicharset(5)

       https://github.com/tesseract-ocr/tesseract/wiki/TrainingTesseract

HISTORY

       unicharset_extractor first appeared in Tesseract 2.00.

COPYING

       Copyright (C) 2006, Google Inc. Licensed under the Apache License, Version 2.0

AUTHOR

       The Tesseract OCR engine was written by Ray Smith and his research groups at Hewlett
       Packard (1985-1995) and Google (2006-present).

                                            04/07/2018                    UNICHARSET_EXTRACTOR(1)