tesseract
1
tesseract
command-line OCR engine
tesseract imagename textbase [configfile] [-l lang]
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
by Google since then.
OPTIONS
imagename
The name of the input image
textbase
The basename of the output file (to which the appropriate extension
will be appended)
configfile
The 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.
-l lang
The language to use. If none is specified, English is assumed.
Tesseract uses 3-character ISO 639-2 language codes. (See LANGUAGES)
-v
Returns the current version of the tesseract(1) executable.
LANGUAGES
There are currently language packs available for the following languages:
Code
Name
bul
Bulgarian
cat
Catalan
ces
Czech
chi_sim
Simplified Chinese
chi_tra
Traditional Chinese
dan
Danish
dan-frak
Danish (Fraktur)
deu
German
ell
Greek
eng
English
fin
Finnish
fra
French
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
spa
Spanish
srp
Serbian
swe
Swedish
tgl
Tagalog
tha
Thai
tur
Turkish
ukr
Ukrainian
vie
Vietnamese
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++. Since
then all the code has been converted to at least compile with a C++ compiler.
Currently it builds under Linux with gcc4.0, gcc4.1 and under Windows with
VC++6 and VC++Express. 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. Another "feature" of the C/C++ split is
that the C++ data structures get converted to C data structures to call
the low-level C code. This is ugly, and the C++izing of the C code
is a step towards eliminating the conversion, but it has not happened yet.
The most important changes in version 2.00 were that Tesseract can now
recognize 6 languages, is fully UTF8 capable, and is fully trainable. See
http://code.google.com/p/tesseract-ocr/wiki/TrainingTesseract
for more information on training.
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. For further details, see the file ReleaseNotes
included with the distribution.
SEE ALSO
tesseract(1)
COPYING
Licensed under the Apache License, Version 2.0