An adaptive zoning technique for efficient word retrieval using dynamic time warping
Angelos Papandreou, Basilis Gatos, Georgios Louloudis · 2014
Zoning features have been proved one of the most efficient statistical features which provide high speed and low complexity word matching. They are calculated by the density of pixels or pattern characteristics in several zones that the pattern frame is divided. In this paper, an adaptive zoning technique for efficient word retrieval is introduced. The main idea is that the zoning features are extracted after adjusting the horizontal boundaries of the zones with the use of Dynamic Time Warping (DTW). This adjustment is performed by coupling every zone of the query word to the corresponding zone of each candidate match-word with the use of the corresponding warping matrix. This process absorbs the ambiguities between the query and the candidate match words. The proposed word retrieval technique is tested using the pixel density as a characteristic feature in every zone and significant improvement is recorded compared to other state-of-the-art methods.