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  NHocr - the Japanese OCR
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1. Introduction

NHocr is a command line OCR (Optical Character Recognition)
program for Japanese language. It has been designed to recognize
machine-printed Japanese characters and some ASCII characters
/symbols in an image.
NHocr is probably the first Open Source Japanese OCR software,
except some experimental, partial codes open to academic
communities.

"nhocr" command reads PBM/PGM/PPM image file(s), recognizes the
text line image for each file, and produces text data in UTF-8.
Each file should contain only ONE horizontal text line image
in line recognition mode, or only ONE text block in block
recognition mode, without any surrounding lines or dirt.

You can also use NHocr through WeOCR service at:
  http://maggie.ocrgrid.org/nhocr/

The program is highly experimental, and the character
recognition performance is limited. (You will be happier
with a commercial product if you want a high performance OCR.)

The character feature used in NHocr is based on Peripheral 
Local Moment (P-LM) proposed by Hori et al. in late 90's.

NHocr is originally a product of the author's weekend
programming. The development work may be rather slow.




2. Installation and configuration

1) O2-tools-2.00 (or newer) is required for building NHocr.
   The source package is available at:
     http://www.imglab.org/p/O2/

   Download O2-tools-2.xx.tar.gz, build it, and install it.


2) Run configure script with --with-O2tools option in the top
   directory. Then, build and install the programs.

  $ ./configure --with-O2tools=<O2tools_directory_on_your_system>
  $ make
  (switch to root if necessary)
  # make install


3) If you want to use dictionary files in a non-standard
   directory, you need to specify the location by setting the
   environment variable NHOCR_DICDIR.

   For example, if the dictionary files are in /opt/nhocr/DIC ,

  $ NHOCR_DICDIR=/opt/nhocr/DIC ; export NHOCR_DICDIR


4) If you want to change the combination of character sets, you
   can set the dictionary codes using the environment variable
   NHOCR_DICCODES.

   For example:

  $ NHOCR_DICCODES=ascii+:zh_CN ; export NHOCR_DICCODES

   The built-in default is ascii+:jpn for ASCII and Japanese
   characters.
  



3. Usage
 
Running nhocr without any argument will show the usage.
A typical usage is:

  $ nhocr -line -o output.txt input.pgm




4. Using NHocr with OCRopus

NHocr can be used as a line recognizer together with OCRopus,
a document analysis and OCR system.

NHocr-OCRopus bridge is included in the package.  See the Lua
scripts in ocropus/ directory.




5. License

See LICENSE file.




For details:
  http://code.google.com/p/nhocr/
  http://sourceforge.jp/projects/nhocr/
--
Dec. 31, 2009  Hideaki Goto,  Tohoku University, Japan