mirror of
https://github.com/tesseract-ocr/tesseract.git
synced 2024-12-13 16:09:04 +08:00
19ddc89c44
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@1131 d0cd1f9f-072b-0410-8dd7-cf729c803f20
261 lines
7.7 KiB
Plaintext
261 lines
7.7 KiB
Plaintext
TESSERACT(1)
|
|
============
|
|
:doctype: manpage
|
|
|
|
NAME
|
|
----
|
|
tesseract - command-line OCR engine
|
|
|
|
SYNOPSIS
|
|
--------
|
|
*tesseract* 'imagename'|'stdin' 'outputbase'|'stdout' [options...] [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.
|
|
|
|
|
|
IN/OUT ARGUMENTS
|
|
----------------
|
|
'imagename'::
|
|
The name of the input image. Most image file formats (anything
|
|
readable by Leptonica) are supported.
|
|
|
|
'stdin'::
|
|
Instruction to read data from standard input
|
|
|
|
'outputbase'::
|
|
The basename of the output file (to which the appropriate extension
|
|
will be appended). By default the output will be named 'outbase.txt'.
|
|
|
|
'stdout'::
|
|
Instruction to sent output data to standard output
|
|
|
|
|
|
OPTIONS
|
|
-------
|
|
'--tessdata-dir /path'::
|
|
Specify the location of tessdata path
|
|
|
|
'--user-words /path/to/file'::
|
|
Specify the location of user words file
|
|
|
|
'--user-patterns /path/to/file specify'::
|
|
The location of user patterns file
|
|
|
|
'-c configvar=value'::
|
|
Set value for control parameter. Multiple -c arguments are allowed.
|
|
|
|
'-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.
|
|
|
|
'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.
|
|
* pdf - Output in pdf instead of a text file.
|
|
|
|
*Nota Bene:* The options '-l lang' and '-psm N' must occur
|
|
before any 'configfile'.
|
|
|
|
|
|
SINGLE OPTIONS
|
|
--------------
|
|
'-v'::
|
|
Returns the current version of the tesseract(1) executable.
|
|
|
|
'--list-langs'::
|
|
list available languages for tesseract engine. Can be used with --tessdata-dir.
|
|
|
|
'--print-parameters'::
|
|
print tesseract parameters to the stdout.
|
|
|
|
|
|
|
|
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'.
|
|
|
|
CONFIG FILES AND AUGMENTING WITH USER DATA
|
|
------------------------------------------
|
|
|
|
Tesseract config files consist of lines with variable-value pairs (space
|
|
separated). The variables are documented as flags in the source code like
|
|
the following one in tesseractclass.h:
|
|
|
|
STRING_VAR_H(tessedit_char_blacklist, "",
|
|
"Blacklist of chars not to recognize");
|
|
|
|
These variables may enable or disable various features of the engine, and
|
|
may cause it to load (or not load) various data. For instance, let's suppose
|
|
you want to OCR in English, but suppress the normal dictionary and load an
|
|
alternative word list and an alternative list of patterns -- these two files
|
|
are the most commonly used extra data files.
|
|
|
|
If your language pack is in /path/to/eng.traineddata and the hocr config
|
|
is in /path/to/configs/hocr then create three new files:
|
|
|
|
/path/to/eng.user-words:
|
|
[verse]
|
|
the
|
|
quick
|
|
brown
|
|
fox
|
|
jumped
|
|
|
|
|
|
/path/to/eng.user-patterns:
|
|
[verse]
|
|
1-\d\d\d-GOOG-411
|
|
www.\n\\\*.com
|
|
|
|
/path/to/configs/bazaar:
|
|
[verse]
|
|
load_system_dawg F
|
|
load_freq_dawg F
|
|
user_words_suffix user-words
|
|
user_patterns_suffix user-patterns
|
|
|
|
Now, if you pass the word 'bazaar' as a trailing command line parameter
|
|
to Tesseract, Tesseract will not bother loading the system dictionary nor
|
|
the dictionary of frequent words and will load and use the eng.user-words
|
|
and eng.user-patterns files you provided. The former is a simple word list,
|
|
one per line. The format of the latter is documented in dict/trie.h
|
|
on read_pattern_list().
|
|
|
|
|
|
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
|