---
name: "unicharset_extractor"
section: "1"
platform: "linux"
package: "tesseract-ocr"
version: "5.5.0-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/unicharset_extractor"
---

# unicharset\_extractor(1)

Reads box or plain text files to extract the unicharset.

## NAME

unicharset\_extractor - 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)](/tesseract/1.md), [unicharset(5)](/unicharset/5.md)

**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).