ANALYTIC WORD RECOGNITION WITHOUT SEGMENTATION BASED ON MARKOV RANDOM FIELDS

Christophe CHOISY and Abdel BELAID

LORIA/CNRS
Campus scientifique, BP 239,
54506 Vandoeuvre­les­Nancy cedex, France
Christophe.Choisy@loria.fr,
Abdel.Belaid@loria.fr

In this paper, a method for analytic handwritten word recognition based on causal Markov random fields is described. The words models are HMMs where each state corresponds to a letter; each letter is modelled by a NSHP­HMM (Markov field). Global models are build dynamically, and used for recognition and learning with the Baum­Welch algorithm. Learning of letter and word models is made using the parameters reestimated on the generated global models. No segmentation is necessary : the system determines itself the best limits between the letters dur­ ing learning. First experiments on a real base of french check amount words give encouraging results of 83.4% for recognition. Keywords : HMM, NSHP­HMM, Cross­learning, Meta­models, Baum­Welch Algorithm.

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. 487-492.