Segmentation-free Word Spotting in Historical Printed Documents

In this paper, a new efficient word spotting methodology is presented that can be applied to historical printed documents without requiring any previous block or word segmentation step. Our aim is to address a methodology which is segmentation-free since in many cases of historical documents, the segmentation process does not produce meaningful results due to unconstraint layout, several degradations or typesetting imperfections. The proposed method is based on block-based document image descriptors that are used at a template matching process satisfying invariance in terms of translation, rotation and scaling. Improvement in terms of time expense is obtained by applying the matching process only on salient regions of the image. Experimental results on a database with representative historical printed documents prove the efficiency of the proposed approach.