tesseract/doc/tesseract.1.asc
david.eger@gmail.com 58e06c8c45 Update man pages for Tesseract 3.02.
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@670 d0cd1f9f-072b-0410-8dd7-cf729c803f20
2012-02-09 22:55:47 +00:00

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TESSERACT(1)
============
:doctype: manpage
NAME
----
tesseract - command-line OCR engine
SYNOPSIS
--------
*tesseract* 'imagename' 'outbase' ['-l lang'] ['-psm N'] ['configfile' ...]
DESCRIPTION
-----------
tesseract(1) is a commercial quality OCR engine originally developed at HP
between 1985 and 1995. In 1995, this engine was among the top 3 evaluated by
UNLV. It was open-sourced by HP and UNLV in 2005, and has been developed
at Google since then.
OPTIONS
-------
'imagename'::
The name of the input image. Most image file formats (anything
readable by Leptonica) are supported.
'outbase'::
The basename of the output file (to which the appropriate extension
will be appended). By default the output will be named 'outbase.txt'.
'-l lang'::
The language to use. If none is specified, English is assumed.
Multiple languages may be specified, separated by plus characters.
Tesseract uses 3-character ISO 639-2 language codes. (See LANGUAGES)
'-psm N'::
Set Tesseract to only run a subset of layout analysis and assume a certain form of image. The options for *N* are:
0 = Orientation and script detection (OSD) only.
1 = Automatic page segmentation with OSD.
2 = Automatic page segmentation, but no OSD, or OCR.
3 = Fully automatic page segmentation, but no OSD. (Default)
4 = Assume a single column of text of variable sizes.
5 = Assume a single uniform block of vertically aligned text.
6 = Assume a single uniform block of text.
7 = Treat the image as a single text line.
8 = Treat the image as a single word.
9 = Treat the image as a single word in a circle.
10 = Treat the image as a single character.
'-v'::
Returns the current version of the tesseract(1) executable.
'configfile'::
The name of a config to use. A config is a plaintext file which
contains a list of variables and their values, one per line, with a
space separating variable from value. Interesting config files
include: +
* hocr - Output in hOCR format instead of as a text file.
*Nota Bene:* The options '-l lang' and '-psm N' must occur
before any 'configfile'.
LANGUAGES
---------
There are currently language packs available for the following languages:
*ara* (Arabic),
*aze* (Azerbauijani),
*bul* (Bulgarian),
*cat* (Catalan),
*ces* (Czech),
*chi_sim* (Simplified Chinese),
*chi_tra* (Traditional Chinese),
*chr* (Cherokee),
*dan* (Danish),
*dan-frak* (Danish (Fraktur)),
*deu* (German),
*ell* (Greek),
*eng* (English),
*enm* (Old English),
*epo* (Esperanto),
*est* (Estonian),
*fin* (Finnish),
*fra* (French),
*frm* (Old French),
*glg* (Galician),
*heb* (Hebrew),
*hin* (Hindi),
*hrv* (Croation),
*hun* (Hungarian),
*ind* (Indonesian),
*ita* (Italian),
*jpn* (Japanese),
*kor* (Korean),
*lav* (Latvian),
*lit* (Lithuanian),
*nld* (Dutch),
*nor* (Norwegian),
*pol* (Polish),
*por* (Portuguese),
*ron* (Romanian),
*rus* (Russian),
*slk* (Slovakian),
*slv* (Slovenian),
*sqi* (Albanian),
*spa* (Spanish),
*srp* (Serbian),
*swe* (Swedish),
*tam* (Tamil),
*tel* (Telugu),
*tgl* (Tagalog),
*tha* (Thai),
*tur* (Turkish),
*ukr* (Ukrainian),
*vie* (Vietnamese)
To use a non-standard language pack named *foo.traineddata*, set the
*TESSDATA_PREFIX* environment variable so the file can be found at
*TESSDATA_PREFIX*/tessdata/*foo*.traineddata and give Tesseract the
argument '-l foo'.
HISTORY
-------
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\+\+.
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.
Version 2.00 brought Unicode (UTF-8) support, six languages, and the ability
to train Tesseract.
Tesseract was included in UNLV's Fourth Annual Test of OCR Accuracy.
See <http://www.isri.unlv.edu/downloads/AT-1995.pdf>. With Tesseract 2.00,
scripts are now included to allow anyone to reproduce some of these tests.
See <http://code.google.com/p/tesseract-ocr/wiki/TestingTesseract> for more
details.
Tesseract 3.00 adds a number of new languages, including Chinese, Japanese,
and Korean. It also introduces a new, single-file based system of managing
language data.
Tesseract 3.02 adds BiDirectional text support, the ability to recognize
multiple languages in a single image, and improved layout analysis.
For further details, see the file ReleaseNotes included with the distribution.
RESOURCES
---------
Main web site: <http://code.google.com/p/tesseract-ocr/> +
Information on training: <http://code.google.com/p/tesseract-ocr/wiki/TrainingTesseract3>
SEE ALSO
--------
ambiguous_words(1), cntraining(1), combine_tessdata(1), dawg2wordlist(1),
shape_training(1), mftraining(1), unicharambigs(5), unicharset(5),
unicharset_extractor(1), wordlist2dawg(1)
AUTHOR
------
Tesseract development was led at Hewlett-Packard and Google by Ray Smith.
The development team has included:
Ahmad Abdulkader, Chris Newton, Dan Johnson, Dar-Shyang Lee, David Eger,
Eric Wiseblatt, Faisal Shafait, Hiroshi Takenaka, Joe Liu, Joern Wanke,
Mark Seaman, Mickey Namiki, Nicholas Beato, Oded Fuhrmann, Phil Cheatle,
Pingping Xiu, Pong Eksombatchai (Chantat), Ranjith Unnikrishnan, Raquel
Romano, Ray Smith, Rika Antonova, Robert Moss, Samuel Charron, Sheelagh
Lloyd, Shobhit Saxena, and Thomas Kielbus.
COPYING
-------
Licensed under the Apache License, Version 2.0