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https://github.com/tesseract-ocr/tessdoc

Tesseract documentation
https://github.com/tesseract-ocr/tessdoc

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README 

        
# Tesseract User Manual



This user manual is for Tesseract versions `5.x`.

For versions `4.x.x`, `3.05.02` and older, see the [documentation for old versions](OldVersionDocs.md).



- [Tesseract User Manual](#tesseract-user-manual)

  * [Introduction](#introduction)

  * [Releases and Changelog](#releases-and-changelog)

  * [Tesseract with LSTM](#tesseract-with-lstm)

  * [5.x.x](#5xx)

    + [Source Code](#source-code)

    + [Binaries](#binaries)

    + [Traineddata Files](#traineddata-files)

    + [Compiling and Installation](#compiling-and-installation)

    + [Usage](#usage)

    + [API Examples](#api-examples)

    + [Technical Information](#technical-information)

    + [Training for Tesseract 5](#training-for-tesseract-5)

    + [Testing](#testing)

    + [External Projects](#external-projects)

  * [User Manual for Old Versions](#user-manual-for-old-versions)



## Introduction



Tesseract is an open source [text recognition (OCR)](https://en.wikipedia.org/wiki/Optical_character_recognition) Engine, available under the [Apache 2.0 license](http://www.apache.org/licenses/LICENSE-2.0).

* Major version 5 is the current stable version and started with release [5.0.0](https://github.com/tesseract-ocr/tesseract/releases/tag/5.0.0) on November 30, 2021.

* Newer minor versions and bugfix versions are available from

[GitHub](https://github.com/tesseract-ocr/tesseract/releases/).

* Latest source code is available from [main branch on GitHub](https://github.com/tesseract-ocr/tesseract/tree/main).

Open issues can be found in [issue tracker](https://github.com/tesseract-ocr/tesseract/issues),

and [planning documentation](https://tesseract-ocr.github.io/tessdoc/Planning.html).



Tesseract can be used directly via [command line](Command-Line-Usage.md), or (for programmers) by using an [API](https://github.com/tesseract-ocr/tesseract/blob/main/include/tesseract/baseapi.h) to extract printed text from images. It supports a [wide variety of languages](Data-Files-in-different-versions.md). Tesseract doesn't have a built-in GUI, but there are several available from the [3rdParty](User-Projects-–-3rdParty.md) page. External tools, wrappers and training projects for Tesseract are listed under [AddOns](AddOns.md).



Tesseract can be used in your own project, under the terms of the [Apache License 2.0.](http://www.apache.org/licenses/LICENSE-2.0) It has a fully featured API, and can be compiled for a variety of targets including Android and the iPhone. See the [3rdParty](User-Projects-–-3rdParty.md) and [AddOns](AddOns.md) pages for samples of what has been done with it.



If you have a question, first read the [documentation](https://tesseract-ocr.github.io/),

particularly the **[FAQ](FAQ.md)** to see if your problem is addressed there.

If not, search the [Issues List](https://github.com/tesseract-ocr/tesseract/issues),

[Tesseract user forum](http://groups.google.com/group/tesseract-ocr),

and if you still can't find what you need, please ask your question in

[Tesseract user forum Google group](http://groups.google.com/group/tesseract-ocr).



Tesseract is free software, so if you want to pitch in and help, please do!

If you find a bug and fix it yourself, the best thing to do is to attach the patch to your bug report in the [Issues List](https://github.com/tesseract-ocr/tesseract/issues).



## Releases and Changelog



- [Release Planning](Planning.md)

- [API/ABI changes review for Tesseract](https://abi-laboratory.pro/?view=timeline&l=tesseract)

- [Downloads](Downloads.md)

- [Releases](https://github.com/tesseract-ocr/tesseract/releases)

- [Release Notes](ReleaseNotes.md)

- [Changelog](https://github.com/tesseract-ocr/tesseract/blob/main/ChangeLog)



## Tesseract with LSTM



Tesseract **4.0** added a new OCR engine based on LSTM neural networks. It works well on x86/Linux with official Language Model data available for [100+ languages and 35+ scripts](Data-Files-in-different-versions.md). See [4.0x-Changelog](tess4/4.0x-Changelog.md) for more details.



## 5.x.x



### Source Code



Tesseract **5.x.x** source code is available in the `main` branch of the [repository](https://github.com/tesseract-ocr/tesseract).

The `main` branch is using `5.0.0` semver versioning because C++ code modernization caused API

incompatibility with 4.x release.



### Binaries



Binaries are available from:

- [Ubuntu - tesseract-ocr-devel PPA](https://launchpad.net/~alex-p/+archive/ubuntu/tesseract-ocr-devel)

- [Debian - notesalexp.org](https://notesalexp.org/tesseract-ocr/#tesseract_5.x)

- [Windows - Tesseract at UB Mannheim](https://github.com/UB-Mannheim/tesseract/wiki)



### Traineddata Files



For detailed information about the different types of models, see [Data Files](Data-Files.md).



Model files for version `4.00` are available from [tessdata tagged 4.00](https://github.com/tesseract-ocr/tessdata/releases/tag/4.00). It has models from November 2016. The individual language file links are available from the following link.

- [tessdata 4.00 November 2016](https://github.com/tesseract-ocr/tessdoc/blob/master/Data-Files.md#data-files-for-version-400-november-29-2016)



Model files for version `4.0.0` and later are available from [tessdata tagged 4.0.0](https://github.com/tesseract-ocr/tessdata/releases/tag/4.0.0).

It has legacy models from September 2017 that have been updated with Integer versions

of `tessdata_best` LSTM models. This set of traineddata files has support for both

the legacy recognizer with `--oem 0` and for LSTM models with `--oem 1`.

These models are available from the following Github repo.

- [tessdata](https://github.com/tesseract-ocr/tessdata)



Two more sets of `official` traineddata, trained at Google, are made available in

the following Github repos. These do not have the legacy models and only have

LSTM models usable with `--oem 1`.



- [tessdata_best](https://github.com/tesseract-ocr/tessdata_best)

- [tessdata_fast](https://github.com/tesseract-ocr/tessdata_fast)



Language model traineddata files same as listed above for version `4.0.0` can be used

with Tesseract `5.x.x`. These are available from:

- [tessdata](https://github.com/tesseract-ocr/tessdata)

- [tessdata_best](https://github.com/tesseract-ocr/tessdata_best)

- [tessdata_fast](https://github.com/tesseract-ocr/tessdata_fast)

- [tessdata_contrib](https://github.com/tesseract-ocr/tessdata_contrib)

- [Links to Community Contributions](Data-Files-Contributions.md)



### Compiling and Installation



- [Compiling and GitInstallation - Linux](Compiling-–-GitInstallation.md)

- [Compiling - Other O/S](Compiling.md)

- [Installation](Installation.md)

- [Docker Containers](Docker-Containers.md)



### Usage



- [Tips to Improve Recognition](ImproveQuality.md)

- [Command Line Usage](Command-Line-Usage.md)

- [Input Formats](InputFormats.md)

- [Viewer Debugging](ViewerDebugging.md)

- [Common Errors and Resolutions](Common-Errors-and-Resolutions.md)

- [Frequently Asked Questions](FAQ.md)



### API Examples



- [API Example](APIExample.md)

- [API Example - user_patterns](APIExample-user_patterns.md)

- [User App Example](User-App-Example.md)

- [C++ Examples](Examples_C++.md)



### Technical Information



- [Historical Technical Documentation](tess3/Technical-Documentation.md)

- [API/ABI changes review for Tesseract](https://abi-laboratory.pro/?view=timeline&l=tesseract)

- [Manual Pages](Documentation.md#manual-pages)

- [Source Documentation generated by Doxygen](Documentation.md#source-documentation-generated-by-Doxygen)

- [Neural Nets in Tesseract](tess4/NeuralNetsInTesseract4.00.md)

- [VGSL Specs](tess4/VGSLSpecs.md)

- [VGSL Specs info from Tensorflow](https://github.com/mldbai/tensorflow-models/blob/master/street/g3doc/vgslspecs.md)

- [Network spec for tessdata_fast models](Data-Files-in-tessdata_fast.md)

- [Network spec for tessdata_best models](Data-Files-in-tessdata_best.md)

- [DAS 2016 tutorial slides](https://github.com/tesseract-ocr/docs/tree/master/das_tutorial2016)

Slides

[#2](https://github.com/tesseract-ocr/docs/blob/main/das_tutorial2016/2ArchitectureAndDataStructures.pdf),

[#6](https://github.com/tesseract-ocr/docs/blob/main/das_tutorial2016/6ModernizationEfforts.pdf),

[#7](https://github.com/tesseract-ocr/docs/blob/main/das_tutorial2016/7Building%20a%20Multi-Lingual%20OCR%20Engine.pdf)

have information about LSTM integration in Tesseract 4.0x.

- [Tesseract OpenCL - Experimental](TesseractOpenCL.md)



### Training for Tesseract 5



Training with `tesstrain.sh` (a.k.a Tesseract 4 training) is unsupported/abandoned.

Please use scripts from [tesseract-ocr/tesstrain](https://github.com/tesseract-ocr/tesstrain) for training.



- [Train Tesseract LSTM with make from Single Line Images and Groundtruth Transcription](https://github.com/tesseract-ocr/tesstrain)

    * [Examples of Training using tesstrain Makefile](https://github.com/tesseract-ocr/tesstrain/wiki)

- [Training LSTM Tesseract 5](tess5/TrainingTesseract-5.md) - based on [detailed Tesseract 4 tutorial and guide by Ray Smith](tess4/TrainingTesseract-4.00.md)



### Testing



- [Benchmarks](Benchmarks.md)

- [TestingTesseract](TestingTesseract.md)

- [UNLV Testing of Tesseract](UNLV-Testing-of-Tesseract.md)



### External Projects



- [AddOns](AddOns.md)

- [User Projects - 3rdParty](User-Projects-–-3rdParty.md)



### User Manual for Old Versions



- [Tesseract 4 Documentation](OldVersionDocs.md#tesseract-4)

- [Tesseract 3 Documentation](OldVersionDocs.md#tesseract-3)