Tree [08c017] master /

File Date Author Commit
 api 2014-06-23 zdenop zdenop [bb4203] fix issue 1228: bilevel pdf output - horizontal...
 ccmain 2014-05-21 [496f67] Bunch of minor bug fixes/cleanups
 ccstruct 2014-05-07 zdenop zdenop [1086fc] skip imagedata build to fix issue 1150 on Mac OS X
 ccutil 2014-06-23 Canming Huang Canming Huang [2450b3] Fixed compilation issue for iOS and OSX.
 classify 2014-04-28 [acc3ad] Fixed some clang errors about explicit construc...
 contrib 2013-11-03 [791b52] fix svn:executable atribute, trailing spaces, v...
 cube 2014-05-21 [496f67] Bunch of minor bug fixes/cleanups
 cutil 2014-01-10 [690028] More minor fixes from issues and cleanup
 dict 2014-05-04 zdenop zdenop [c216d7] fix issue 123: user-words (and user-patterns) f...
 doc 2013-09-26 [3bf503] autotools: check for icu library, implement 'ma...
 java 2014-01-30 [7c9854] Cleaner fix for issue 1075
 neural_networks 2014-01-25 [595886] Fixed a lot of compiler/clang warnings
 opencl 2014-06-08 zdenop zdenop [664495] fix issue 1043
 tessdata 2014-04-24 [e33525] Undoing accidental modification to eng.traineddata
 testing 2014-03-07 [eccfde] move testing images to testing directory
 textord 2014-05-21 [496f67] Bunch of minor bug fixes/cleanups
 training 2014-05-21 [496f67] Bunch of minor bug fixes/cleanups
 viewer 2014-04-28 [acc3ad] Fixed some clang errors about explicit construc...
 vs2008 2014-06-22 zdenop zdenop [89a2fc] put info about (API) version; fix typo
 vs2010 2014-06-22 zdenop zdenop [89a2fc] put info about (API) version; fix typo
 wordrec 2014-04-24 [d83571] Fixed issue 1101
 AUTHORS 2013-01-03 [f9fd19] Integrated patch to AUTHORS fixing issue 814 an...
 COPYING 2011-10-22 [45a06a] removed BOM form strngs.h, updated NSIS script ...
 ChangeLog 2014-02-05 [15e3a7] Updated ChangeLog for 3.03 rc1
 INSTALL 2012-02-05 [f37cc8] install data files; small fix of INSTALL, READM...
 INSTALL.SVN 2013-10-31 [68e53d] add VS2010 solution and update VS2008 solution 2014-03-28 zdenop zdenop [79c362] add training directory to 'make clean' and 'mak...
 NEWS 2007-03-07 tmbdev tmbdev [69dc72] cleaning up trunk
 README 2012-09-24 [d5af73] C-API (fix issue 362)
 ReleaseNotes 2012-02-02 [67bcbb] Remaining misc changes for 3.02 2014-01-14 [e92d4a] Fixed 2014-07-01 zdenop zdenop [ce7ed3] revert commit r1122 ;-)
 makemoredists 2012-11-01 [6d106f] fix tarball portability 2014-01-31 zdenop zdenop [f07e30] check for leptonica version; add info to tesser...

Read Me

Note that this is a text-only and possibly out-of-date version of the 
wiki ReadMe, which is located at:


This package contains the Tesseract Open Source OCR Engine.
Originally developed at Hewlett Packard Laboratories Bristol and
at Hewlett Packard Co, Greeley Colorado, all the code
in this distribution is now licensed under the Apache License:

** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** See the License for the specific language governing permissions and
** limitations under the License.

Dependencies and Licenses

Leptonica is required. ( Tesseract no longer compiles
without Leptonica.
Libtiff is no longer required as a direct dependency.

Installing and Running Tesseract

All Users Do NOT Ignore!
The tarballs are split into pieces.

tesseract-x.xx.tar.gz contains all the source code.

tesseract-x.xx.<lang>.tar.gz contains the language data files for <lang>.
You need at least one of these or Tesseract will not work.

Note that tesseract-x.xx.tar.gz unpacks to the tesseract-ocr directory.
tesseract-x.xx.<lang>.tar.gz unpacks to the tessdata directory which 
belongs inside your tesseract-ocr directory. It is therefore best to 
download them into your tesseract-x.xx directory, so you can use unpack 
here or equivalent. You can unpack as many of the language packs as you 
care to, as they all contain different files. Note that if you are using
make install you should unpack your language data to your source tree 
before you run make install. If you unpack them as root to the 
destination directory of make install, then the user ids and access
permissions might be messed up.

boxtiff-2.xx.<lang>.tar.gz contains data that was used in training for 
those that want to do their own training. Most users should NOT download
these files.

Instructions for using the training tools are documented separately at 
Tesseract wiki


Please use installer (for 3.00 and above). Tesseract is library with 
command line interface. If you need GUI, please check AddOns wiki page

If you are building from the sources, the recommended build platform is 
VC++ Express 2008 (optionally 2010).

The executables are built with static linking, so they stand more chance
of working out of the box on more windows systems.

The executable must reside in the same directory as the tessdata 
directory or you need to set up environment variable TESSDATA_PREFIX.
Installer will set it up for you.

The command line is:

tesseract imagename outputbase [-l lang] [-psm pagesegmode] [configfiles...]

If you need interface to other applications, please check wrapper section
on AddOns wiki page:

Non-Windows (or Cygwin)

You have to tell Tesseract through a standard unix mechanism where to 
find its data directory. You must either:

make install
sudo ldconfig

to move the data files to the standard place, or:

export TESSDATA_PREFIX="directory in which your tessdata resides/"

In either case the command line is:

tesseract imagename outputbase [-l lang] [-psm pagesegmode] [configfiles...]

New there is a tesseract.spec for making rpms. (Thanks to Andrew Ziem for
the help.) It might work with your OS if you know how to do that.

If you are linking to the libraries, as Ocropus does, please link to

The engine was developed at Hewlett Packard Laboratories Bristol and
at Hewlett Packard Co, Greeley Colorado between 1985 and 1994, with some
more changes made in 1996 to port to Windows, and some C++izing in 1998.
A lot of the code was written in C, and then some more was written in C++.
Since then all the code has been converted to at least compile with a C++
compiler. Currently it builds under Linux with gcc4.4.3 and under Windows
with VC++2008. The C++ code makes heavy use of a list system using macros.
This predates stl, was portable before stl, and is more efficient than stl
lists, but has the big negative that if you do get a segmentation violation,
it is hard to debug.

The most recent change is that Tesseract can now recognize 39 languages,
including Arabic, Hindi, Vietnamese, plus 3 Fraktur variants 
is fully UTF8 capable, and is fully trainable. See TrainingTesseract for
more information on training.

Tesseract was included in UNLV's Fourth Annual Test of OCR Accuracy. 
Results were available on
With Tesseract 2.00, scripts were included to allow anyone to reproduce 
some of these tests. See TestingTesseract for more details. 

About the Engine
This code is a raw OCR engine. It has limited PAGE LAYOUT ANALYSIS, simple
OUTPUT FORMATTING (txt, hocr/html), and NO UI. 
Having said that, in 1995, this engine was in the top 3 in terms of character
accuracy, and it compiles and runs on both Linux and Windows.
As of 3.01, Tesseract is fully unicode (UTF-8) enabled, and can recognize 39
languages "out of the box." Code and documentation is provided for the brave
to train in other languages. See for more
information on training.