UNICHARSET_EXTRACTOR(1)
=======================

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
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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).
