Alphanumeric Character Recognizer 1.0

Overview

The Lipi Alphanumeric Character Recognizer Package lipi-reco-char-alphanum 1.0 contains separate “pre-built” recognizers for isolated handwritten English uppercase characters, lowercase characters and numerals in digital ink form captured using an electronic stylus. They are built using the Lipi Toolkit and are meant for users interested in integrating such recognition capabilities into an application.

These recognizers are not meant to represent the state of the art in recognition technology, but rather provided for the purpose of creating interesting new applications.

The recognizer package comes with three pre-built shape recognizers:

• Numerals: For Indo-Arabic numerals [0-9].
• Eng_upper: For uppercase English alphabet [A-Z].
• Eng_lower: For lowercase English alphabet [a-z].

Package Contents

The package contains dynamic libraries, configuration files and model data files for the three recognizers.

Supported Platforms

lipi-reco-char-alphanum 1.0 comes in versions for Windows and Linux, and has been tested on the following platforms:

• Windows XP Professional
• Windows 2000 Professional edition
• Red hat Enterprise Linux Edition 3.0
• GNU Linux 2.6.9.22
• GNU Linux (Ubuntu) 2.6.14.6

System Requirements

Disk Requirements

lipi-reco-char-alphanum1.0 packages for Windows and Linux are 5.3 MB in size and require 13.9 MB of space after extraction.

Software Requirements

Windows

• Microsoft Visual Studio 6.0 with SP6 ( http://msdn.microsoft.com/vstudio/)
• Cabarc sdk (required for packaging only) ( http://support.microsoft.com/default.aspx?scid=kb;en-us;310618)

Linux

• GCC 3.3.3 ( http://gcc.gnu.org/)
• tar

Recognition Accuracy

The built recognizers use Dynamic Time Warping (DTW) shape recognition method and have been trained and bencharked using the IRONOFF handwriting database. For more details please see the lipi-reco-char-alphanum User Manual.

Enhancements & Bugs Fixed

This is the first version of pre-built recognizers.

Known Issues

• On Windows platforms, if the STL’s string data type is used in a client application and passed by reference
  to a DLL function, the application crashes when the string variable goes out of scope. This is a known
  defect in Microsoft’s STL library. For details see: http://support.microsoft.com/default.aspx?scid=kb;en-us;813810 
  Workaround
  Refer to:
  • http://support.microsoft.com/default.aspx?scid=kb;en-us;813810
  • http://www.dinkumware.com/vc_fixes.html
• A bug in the normalizeSize function causes accuracy to be impacted negatively.

  Workaround

  • Reset CaptureDevice before every call to recognize function. Please see Release Notes for details.

Backward Compatibility

This is the first version of built recognizers.

Compatibility with Lipi Core Toolkit

The recognizers are built using the version 1.1 of the core toolkit.

Documents

lipi-reco-char-alphanum 1.0 comes with following documents.

• User Manual
• Release notes

Contributors

• Mandalapu Dinesh, HPL
• Nidhi Sharma, HP GDIC

Acknowledgements

We would like to thank IRESTE, University of Nantes (France) for allowing the use of the IRONOFF handwriting database for training the pre-built recognizers. For more information about this database, visit  http://www.infres.enst.fr/~elc/GRCE/news/IRONOFF.doc.