A voting-based technique for word spotting in handwritten document images

Word spotting in handwritten document images is a field of immense interest due to its widespread applications. Recognition-free and recognition-based approaches are the two comprehensively studied regimes for the said problem out of which the first one is more realistic for practical applications. In literature, several works have been found that have used contour and distance-based measures for matching of the profiles of two word images. Although this is a prudent choice for printed words, the same often faces bottlenecks for unconstrained handwriting. To this end, this work applies dynamic time warping algorithm on logarithmic profiles of handwritten word images to lessen the uncontrolled profile variation that occurs due to elongation while writing some characters. We have considered both global and local interpretations of a word image by dividing it vertically into a number of sub-parts. This multi-view analysis provides close-up views of different approximations for the same word image. Finally, a voting scheme is evoked to produce the final decision. Besides, we have adopted a pruning method to pre-filter the target word images prior to applying the voting-based word matching scheme. The method has been tested on word images, taken from Qatar University Writer Identification database. We have obtained satisfactory results as compared to many state-of-the-art methods that also include deep learning-based feature extraction models.

Automated summary

This paper focuses on word spotting in handwritten document images, utilizing the dynamic time warping algorithm to process the logarithmic profiles of word images and reduce uncontrolled profile variations in unconstrained handwriting.