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unicharset_extractor \- extract unicharset from Tesseract boxfiles

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\fBunicharset_extractor\fR \fI[\-D dir]\fR \fIFILE\fR\&...

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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:

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.if n \{\

.RS 4

.\}

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unicharset_extractor fontfile_1\&.box fontfile_2\&.box \&.\&.\&.

.fi

.if n \{\

.RE

.\}

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The unicharset will be put into the file \fIdir/unicharset\fR, or simply \fI\&./unicharset\fR if no output directory is provided\&.

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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))

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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\&.

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\fBNOTE\fR 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\&.

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tesseract(1), unicharset(5)

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unicharset_extractor first appeared in Tesseract 2\&.00\&.

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Copyright (C) 2006, Google Inc\&. Licensed under the Apache License, Version 2\&.0

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