ADAPTIVE CHARACTER RECOGNIZER FOR A HAND­HELD DEVICE: IMPLEMENTATION AND EVALUATION SETUP

Vuokko VUORI, Matti AKSELA, Jorma LAAKSONEN, Erkki OJA

Helsinki University of Technology
Laboratory of Computer and Information Science
P.O.Box 5400, FIN­02015 HUT, Finland
email: {vuokko.vuori,matti.aksela,jorma.laaksonen}@hut.fi

JARI KANGAS

Nokia Research Center
P.O.Box 100, FIN­33701 Tampere, Finland
email: jari.a.kangas@nokia.com

In this work, we describe a character recognition system we have implemented for experimenting with self­supervised adaptation method. The Dynamic Time Warping algorithm is used for matching input characters to prototypes and recognition is carried out according to the k­nearest neighbor rule. The prototype set is adapted by adding new prototypes into the prototype set and reshaping existing ones with a method based on the Learning Vector Quantization. The adaptation process is supervised by the user's reactions to the recognition results and other indirect information obtained from the user interface of text input. We also discuss the practical problems encountered in the implementation of a computationally heavy recognition method into a device with limited resources.

In: L.R.B. Schomaker and L.G. Vuurpijl (Eds.)
Proceedings of the Seventh International Workshop on Frontiers
in Handwriting Recognition, September 11-13 2000, Amsterdam,
Nijmegen: International Unipen Foundation,
ISBN 90-76942-01-3
pp. 13-22