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COMBINE_TESSDATA(1)					     COMBINE_TESSDATA(1)

NAME
     combine_tessdata - combine/extract/overwrite/list/compact Tesseract data

SYNOPSIS
     combine_tessdata [OPTION] FILE...

DESCRIPTION
     combine_tessdata(1)   is	the   main   program   to  combine/extract/over-
     write/list/compact tessdata components in [lang].traineddata files.

     To combine all the individual tessdata components (unicharset, DAWGs, clas-
     sifier  templates,  ambiguities,  language  configs)   located   at,   say,
     /home/$USER/temp/eng.* run:

	 combine_tessdata /home/$USER/temp/eng.

     The  result  will be a combined tessdata file /home/$USER/temp/eng.trained-
     data

     Specify option -e if you would like to extract individual components from a
     combined traineddata file. For example, to extract language config file and
     the unicharset from tessdata/eng.traineddata run:

	 combine_tessdata -e tessdata/eng.traineddata \
	   /home/$USER/temp/eng.config /home/$USER/temp/eng.unicharset

     The   desired   config   file   and   unicharset	will   be   written   to
     /home/$USER/temp/eng.config /home/$USER/temp/eng.unicharset

     Specify   option  -o  to  overwrite  individual  components  of  the  given
     [lang].traineddata file. For example,  to	overwrite  language  config  and
     unichar ambiguities files in tessdata/eng.traineddata use:

	 combine_tessdata -o tessdata/eng.traineddata \
	   /home/$USER/temp/eng.config /home/$USER/temp/eng.unicharambigs

     As  a result, tessdata/eng.traineddata will contain the new language config
     and unichar ambigs, plus all the original DAWGs, classifier templates, etc.

     Note: the file names of the files to  extract  to	and  to  overwrite  from
     should  have  the	appropriate  file suffixes (extensions) indicating their
     tessdata component type (.unicharset for the unicharset, .unicharambigs for
     unichar ambigs, etc).  See  k*FileSuffix  variable  in  ccutil/tessdataman-
     ager.h.

     Specify option -u to unpack all the components to the specified path:

	 combine_tessdata -u tessdata/eng.traineddata /home/$USER/temp/eng.

     This will create /home/$USER/temp/eng.* files with individual tessdata com-
     ponents from tessdata/eng.traineddata.

OPTIONS
     -c  .traineddata  FILE...:  Compacts the LSTM component in the .traineddata
     file to int.

     -d .traineddata FILE...: Lists directory of components from  the  .trained-
     data file.

     -e  .traineddata  FILE...:  Extracts  the	specified  components  from  the
     .traineddata file

     -l .traineddata FILE...: List the network information.

     -o  .traineddata  FILE...:  Overwrites  the  specified  components  of  the
     .traineddata file with those provided on the command line.

     -u .traineddata PATHPREFIX Unpacks the .traineddata using the provided pre-
     fix.

CAVEATS
     Prefix refers to the full file prefix, including period (.)

COMPONENTS
     The components in a Tesseract lang.traineddata file as of Tesseract 4.0 are
     briefly  described  below; For more information on many of these files, see
     https://tesseract-ocr.github.io/tessdoc/Training-Tesseract.html	     and
     https://tesseract-ocr.github.io/tessdoc/TrainingTesseract-4.00.html

     lang.config
	 (Optional) Language-specific overrides to default config variables. For
	 4.0  traineddata  files,  lang.config provides control parameters which
	 can affect layout analysis, and sub-languages.

     lang.unicharset
	 (Required - 3.0x legacy tesseract) The list of symbols  that  Tesseract
	 recognizes, with properties. See unicharset(5).

     lang.unicharambigs
	 (Optional  -  3.0x  legacy tesseract) This file contains information on
	 pairs of recognized symbols which are often confused. For  example,  rn
	 and m.

     lang.inttemp
	 (Required  -  3.0x legacy tesseract) Character shape templates for each
	 unichar. Produced by mftraining(1).

     lang.pffmtable
	 (Required - 3.0x legacy tesseract) The number of features expected  for
	 each unichar. Produced by mftraining(1) from .tr files.

     lang.normproto
	 (Required  -  3.0x legacy tesseract) Character normalization prototypes
	 generated by cntraining(1) from .tr files.

     lang.punc-dawg
	 (Optional - 3.0x legacy tesseract) A dawg made  from  punctuation  pat-
	 terns	found  around  words.  The  "word"  part is replaced by a single
	 space.

     lang.word-dawg
	 (Optional - 3.0x legacy tesseract) A dawg made  from  dictionary  words
	 from the language.

     lang.number-dawg
	 (Optional - 3.0x legacy tesseract) A dawg made from tokens which origi-
	 nally contained digits. Each digit is replaced by a space character.

     lang.freq-dawg
	 (Optional  -  3.0x legacy tesseract) A dawg made from the most frequent
	 words which would have gone into word-dawg.

     lang.fixed-length-dawgs
	 (Optional - 3.0x legacy tesseract) Several  dawgs  of	different  fixed
	 lengths -- useful for languages like Chinese.

     lang.shapetable
	 (Optional - 3.0x legacy tesseract) When present, a shapetable is an ex-
	 tra layer between the character classifier and the word recognizer that
	 allows  the  character classifier to return a collection of unichar ids
	 and fonts instead of a single unichar-id and font.

     lang.bigram-dawg
	 (Optional - 3.0x legacy tesseract) A dawg of  word  bigrams  where  the
	 words are separated by a space and each digit is replaced by a ?.

     lang.unambig-dawg
	 (Optional - 3.0x legacy tesseract) .

     lang.params-model
	 (Optional - 3.0x legacy tesseract) .

     lang.lstm
	 (Required - 4.0 LSTM) Neural net trained recognition model generated by
	 lstmtraining.

     lang.lstm-punc-dawg
	 (Optional  -  4.0  LSTM)  A  dawg  made from punctuation patterns found
	 around words. The "word" part is  replaced  by  a  single  space.  Uses
	 lang.lstm-unicharset.

     lang.lstm-word-dawg
	 (Optional  -  4.0 LSTM) A dawg made from dictionary words from the lan-
	 guage. Uses lang.lstm-unicharset.

     lang.lstm-number-dawg
	 (Optional - 4.0 LSTM) A dawg made from  tokens  which	originally  con-
	 tained  digits.  Each	digit  is  replaced  by  a space character. Uses
	 lang.lstm-unicharset.

     lang.lstm-unicharset
	 (Required - 4.0 LSTM) The unicode character set that  Tesseract  recog-
	 nizes,  with properties. Same unicharset must be used to train the LSTM
	 and build the lstm-*-dawgs files.

     lang.lstm-recoder
	 (Required - 4.0 LSTM) Unicharcompress, aka the recoder, which maps  the
	 unicharset  further  to  the  codes actually used by the neural network
	 recognizer. This is created as part of the starter traineddata by  com-
	 bine_lang_model.

     lang.version
	 (Optional)  Version  string for the traineddata file. First appeared in
	 version 4.0 of Tesseract. Old version of traineddata files will  report
	 Version:Pre-4.0.0.  4.0  version  of  traineddata files may include the
	 network spec used for LSTM training as part of version string.

HISTORY
     combine_tessdata(1) first appeared in version 3.00 of Tesseract

SEE ALSO
     tesseract(1),     wordlist2dawg(1),      cntraining(1),	  mftraining(1),
     unicharset(5), unicharambigs(5)

COPYING
     Copyright	(C) 2009, Google Inc. Licensed under the Apache License, Version
     2.0

AUTHOR
     The Tesseract OCR engine was written by Ray Smith and his	research  groups
     at Hewlett Packard (1985-1995) and Google (2006-2018).

				   08/27/2026		     COMBINE_TESSDATA(1)
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