A new methodology for gray-scale character segmentation and recognition

Generally speaking through the binarization of gray-scale images useful information for the segmentation of touched or overlapped characters may be lost in many cases. If we analyze grayscale images however specific topographic features and the variation of intensities can be observed in the character boundaries. We believe that such kinds of clues obtained from gray-scale images may work for efficient character segmentation and recognition. In this paper we propose a new methodology for character segmentation and recognition which makes the best use of the characteristics of grayscale images. In the proposed methodology the character segmentation regions are determined by using projection profiles and topographic features extracted from the gray-scale images. Then a nonlinear character segmentation path in each character segmentation region is found by using multi-stage graph search algorithm. Finally in order to confirm the nonlinear character segmentation paths and recognition results recognition-based segmentation method is adopted. Through the experiments with various kinds of printed documents it is convinced that the proposed methodology is very effective for the segmGntation and recognition of touched and overlapped characters.