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tesseract(1)

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

   afr (Afrikaans) amh (Amharic) ara (Arabic) asm (Assamese) aze
   (Azerbaijani) aze_cyrl (Azerbaijani - Cyrilic) bel (Belarusian) ben
   (Bengali) bod (Tibetan) bos (Bosnian) bul (Bulgarian) cat (Catalan;
   Valencian) ceb (Cebuano) ces (Czech) chi_sim (Chinese - Simplified)
   chi_tra (Chinese - Traditional) chr (Cherokee) cym (Welsh) dan (Danish)
   dan_frak (Danish - Fraktur) deu (German) deu_frak (German - Fraktur)
   dzo (Dzongkha) ell (Greek, Modern (1453-)) eng (English) enm (English,
   Middle (1100-1500)) epo (Esperanto) equ (Math / equation detection
   module) est (Estonian) eus (Basque) fas (Persian) fin (Finnish) fra
   (French) frk (Frankish) frm (French, Middle (ca.1400-1600)) gle (Irish)
   glg (Galician) grc (Greek, Ancient (to 1453)) guj (Gujarati) hat
   (Haitian; Haitian Creole) heb (Hebrew) hin (Hindi) hrv (Croatian) hun
   (Hungarian) iku (Inuktitut) ind (Indonesian) isl (Icelandic) ita
   (Italian) ita_old (Italian - Old) jav (Javanese) jpn (Japanese) kan
   (Kannada) kat (Georgian) kat_old (Georgian - Old) kaz (Kazakh) khm
   (Central Khmer) kir (Kirghiz; Kyrgyz) kor (Korean) kur (Kurdish) lao
   (Lao) lat (Latin) lav (Latvian) lit (Lithuanian) mal (Malayalam) mar
   (Marathi) mkd (Macedonian) mlt (Maltese) msa (Malay) mya (Burmese) nep
   (Nepali) nld (Dutch; Flemish) nor (Norwegian) ori (Oriya) osd
   (Orientation and script detection module) pan (Panjabi; Punjabi) pol
   (Polish) por (Portuguese) pus (Pushto; Pashto) ron (Romanian;
   Moldavian; Moldovan) rus (Russian) san (Sanskrit) sin (Sinhala;
   Sinhalese) slk (Slovak) slk_frak (Slovak - Fraktur) slv (Slovenian) spa
   (Spanish; Castilian) spa_old (Spanish; Castilian - Old) sqi (Albanian)
   srp (Serbian) srp_latn (Serbian - Latin) swa (Swahili) swe (Swedish)
   syr (Syriac) tam (Tamil) tel (Telugu) tgk (Tajik) tgl (Tagalog) tha
   (Thai) tir (Tigrinya) tur (Turkish) uig (Uighur; Uyghur) ukr
   (Ukrainian) urd (Urdu) uzb (Uzbek) uzb_cyrl (Uzbek - Cyrilic) vie
   (Vietnamese) yid (Yiddish)

   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:

       the
       quick
       brown
       fox
       jumped

   /path/to/eng.user-patterns:

       1-\d\d\d-GOOG-411
       www.\n\\\*.com

   /path/to/configs/bazaar:

       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 https://github.com/tesseract-ocr/docs/blob/master/AT-1995.pdf. With
   Tesseract 2.00, scripts are now included to allow anyone to reproduce
   some of these tests. See
   https://github.com/tesseract-ocr/tesseract/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: https://github.com/tesseract-ocr Information on
   training:
   https://github.com/tesseract-ocr/tesseract/wiki/TrainingTesseract

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

                              06/28/2015                      TESSERACT(1)

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