@Article{JoseAntonioRodriguez2009, author="Jose Antonio Rodriguez and Florent Perronnin", title="Handwritten word-spotting using hidden Markov models and universal vocabularies", journal="Pattern Recognition", year="2009", publisher="Elsevier", volume="42", number="9", pages="2103--2116", optkeywords="Word-spotting", optkeywords="Hidden Markov model", optkeywords="Score normalization", optkeywords="Universal vocabulary", optkeywords="Handwriting recognition", abstract="Handwritten word-spotting is traditionally viewed as an image matching task between one or multiple query word-images and a set of candidate word-images in a database. This is a typical instance of the query-by-example paradigm. In this article, we introduce a statistical framework for the word-spotting problem which employs hidden Markov models (HMMs) to model keywords and a Gaussian mixture model (GMM) for score normalization. We explore the use of two types of HMMs for the word modeling part: continuous HMMs (C-HMMs) and semi-continuous HMMs (SC-HMMs), i.e. HMMs with a shared set of Gaussians. We show on a challenging multi-writer corpus that the proposed statistical framework is always superior to a traditional matching system which uses dynamic time warping (DTW) for word-image distance computation. A very important finding is that the SC-HMM is superior when labeled training data is scarce---as low as one sample per keyword---thanks to the prior information which can be incorporated in the shared set of Gaussians.", optnote="exported from refbase (http://refbase.cvc.uab.es/show.php?record=1053), last updated on Thu, 19 Dec 2013 12:26:24 +0100", issn="0031-3203", doi="10.1016/j.patcog.2009.02.005" }