Provided by: ocrodjvu_0.10.4-1_all bug


       ocrodjvu - OCR for DjVu files


       ocrodjvu {-o | --save-bundled} output-djvu-file [option...] djvu-file

       ocrodjvu {-i | --save-indirect} index-djvu-file [option...] djvu-file

       ocrodjvu --save-script script-file [option...] djvu-file

       ocrodjvu --in-place [option...] djvu-file

       ocrodjvu --dry-run [option...] djvu-file

       ocrodjvu {--version | --help | -h | --list-engines | --list-languages}


       ocrodjvu is a wrapper for OCR systems that allows you to perform OCR on DjVu files.

       The following OCR engines are supported:

       ·   OCRopus[1] (internally, ocrodjvu calls ocroscript's recognize (or rec-tess) command,
           so that ultimately Tesseract acts as the OCR backend);

       ·   Cuneiform for Linux[2].

       ·   Ocrad[3].

       ·   GOCR[4].

       ·   Stand-alone Tesseract[5].


   OCR engine options
       -e, --engine=engine-id
           Use this OCR engine.

           The default is “tesseract”. (The default was “ocropus” prior to ocrodjvu 0.8.)

           Print list of available OCR engines.

   Options controlling output
       -o, --save-bundled=output-djvu-file
           Save OCR results as a bundled multi-page document into output-djvu-file.

       -i, --save-indirect=index-djvu-file
           Save OCR results as an indirect multi-page document. Use index-djvu-file as the index
           file name; put the component files into the same directory. The directory must exist
           and be writable.

           Save a djvused script with OCR results into script-file.

           Save OCR results in place.

           (Use this option to retain compatibility with ocrodjvu < 0.2.)

           Don't change any files, throw OCR results away.

       It is mandatory to use exactly one of the above options.

           If OCR results are to be saved to a separate document (-o/--save-bundled or
           -i/--save-indirect), save only the pages selected for OCR.

           The default is to save all pages, even when the -p/--pages option is in effect.

           Remove existing hidden text if present in the pages not selected for OCR.

           (Use this option to retain compatibility with ocrodjvu < 0.2.)

           Save raw OCR results (typically in the hOCR format) into output-directory. The
           directory must exist and be writable.

           Specifies the file naming scheme for raw OCR results.

           The template language uses the Python string formatting syntax[6]. The following
           fields are available:

           page, page+N, page-N
               page number, optionally shifted by a number N

               page identifier

               page identifier without file extension

           The default template is “{id-ext}”.

   Text segmentation options
       -t lines, --details lines
           Record location of every line. Don't record locations of particular words or

           This is the default for OCRopus 0.2. The option is ineffective with stand-alone
           Tesseract 2.0.

       -t words, --details=words
           Record location of every line and every word. Don't record locations of particular

           This is the default for most OCR engines.

           This option is ineffective with OCRopus 0.2 and stand-alone Tesseract 2.0.

       -t chars, --details=chars
           Record location of every line, every word and every character.

           This option is ineffective with OCRopus 0.2 and stand-alone Tesseract 2.0.

           Consider each non-empty sequence of non-whitespace characters a single word.

           This is the default, despite being linguistically incorrect.

           Use the Unicode Text Segmentation[7] algorithm to break lines into words.

           This option breaks assumptions of some DjVu tools that words are separated by spaces,
           and therefore it is not recommended.

   Other options
       -l, --language=language-id
           Set recognition language.  language-id is typically an ISO 639-2/T three-letter code.

           Tesseract ≥ 3.02 allows specifying multiple languages separated by “+” characters.

           For OCRopus, the default is “eng” (English), unless the tesslanguage environment
           variable is set. For other OCR engines, the default is always “eng”.

           Print list of available languages for the currently selected OCR engine.

           Render only masks of page images.

           This is the default.

           Render only foreground layers of page images.

           Render all layers of page images.

           This option is necessary to OCR DjVu files with invalid foreground/background

       -p, --pages=page-range
           Specifies pages to process.  page-range is a comma-separated list of sub-ranges. Each
           sub-range is either a single page (e.g. 17) or a contiguous range of pages
           (e.g. 37-42). Pages are numbered from 1.

           The default is to process all pages.

       -j, --jobs=n
           Start up to n OCR processes.

           Output version information and exit.

       -h, --help
           Display help and exit.

   Advanced options
       -D, --debug
           To ease debugging, don't delete intermediate files.

       -X key=value
           This option allows controlling some details of how ocrodjvu operates.

           Stop program execution when an exceptional situation (e.g., malformed output from the
           OCR engine, internal ocrodjvu error, etc.) occurs.

           This is the default.

           Attempt to recover from exceptional situations.

           This option is strongly discouraged.

           Use a HTML5 parser[8], which is more robust but slower than the default parser.


       One of the following exit values can be returned by ocrodjvu:

           The program finished successfully.

           A fatal error occurred.

           The program recovered from an error (--on-error=resume).


       The following environment variables affects ocrodjvu:

           Recognition language for Tesseract.

           (Use this variable is deprecated in favor of the --language option.)

           ocrodjvu makes heavy use of temporary files. It will store them in a directory
           specified by this variable. The default is /tmp.


   Known bugs
       Tesseract 3.00 is affected by a bug [9] making it produce invalid hOCR output in certain
       circumstances. ocrodjvu does not try recover form this fault (which couldn't be done
       reliably anyway) unless you pass the -X fix-html=1 option.

       When using Tesseract ≥ 3.00, extracting bounding boxes of particular characters (which
       happens when either --details=chars or --word-segmentation=uax29) is inefficient. This is
       due to limitations of the Tesseract command-line interface.

   Reporting new bugs
       Please report bugs at:


       djvu(1), djvu2hocr(1), hocr2djvused(1),

       ocroscript(1), tesseract(1), cuneiform(1), ocrad(1), gocr(1)


        1. OCRopus

        2. Cuneiform for Linux

        3. Ocrad

        4. GOCR

        5. Tesseract

        6. Python string formatting syntax

        7. Unicode Text Segmentation

        8. HTML5 parser