Writer independent on-line handwriting recognition using an HMM approach

In this paper we describe a Hidden Markov Model (HMM) based writer independent handwriting recognition system. A combination of signal normalization preprocessing and the use of invariant features makes the system robust with respect to variability among di!erent writers as well as di!erent writing environments and ink collection mechanisms. A combination of point oriented and stroke oriented features yields improved accuracy. Language modeling constrains the hypothesis space to manageable levels in most cases. In addition a two-pass N-best approach is taken for large vocabularies. We report experimental results for both character and word recognition on several UNIPEN datasets, which are standard datasets of English text collected from around the world. ( 1999 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved.