Recognition and verification of unconstrained handwritten words
Recognition and verification of unconstrained handwritten words
Koerich, Alessandro L. and Sabourin, Robert and Suen, Ching Y.
IEEE Transactions on Pattern Analysis and Machine Intelligence 2005
Abstract : This paper presents a novel approach for the verification of the word hypotheses generated by a large vocabulary, offline handwritten word recognition system. Given a word image, the recognition system produces a ranked list of the N-best recognition hypothepes consisting of text transcripts, segmentation boundaries of the word hypotheses into characters, and recognition scores. The verification consists of an estimation of the probability of each segment representing a known class of character. Then, character probabi ities are combined to produce word confidence scores which are further integrated with the recognition scores produced by the recogni ion system. The N-best recognition hypothesis list is reranked based on such composite scores. In the end, rejection rules are invoke to either accept the best recognition hypothesis of such a list orto reject the input word image. The use of the verification approach has im oved the word recognition rate as well as the reliability of the recognition system, while not causing significant delays in the recogni ion process. Our approach is described in detail and the experimental results on a large database of unconstrained handwritten words extracted from postal envelopes are presented. © 2005 IEEE.
