unicharset_extractor - Man Page

Reads box or plain text files to extract the unicharset​.

Synopsis

unicharset_extractor [--output_unicharset filename] [--norm_mode mode] box_or_text_file [​...]

Where mode means: 1=combine graphemes (use for Latin and other simple scripts) 2=split graphemes (use for Indic/Khmer/Myanmar) 3=pure unicode (use for Arabic/Hebrew/Thai/Tibetan)

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 training pages bounding box files or a plain text file:

unicharset_extractor fontfile_1​.box fontfile_2​.box ​.​.​.

The unicharset will be put into the file ​./unicharset if no output filename is provided​.

NOTE Use the appropriate norm_mode based on the language​.

See Also

tesseract(1), unicharset(5)

https://tesseract-ocr​.github​.io/tessdoc/Training-Tesseract​.html

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 (2006-2018)​.

Info

09/21/2026