Line-touching character recognition based on dynamic reference feature synthesis

In recognizing characters written on forms, it often happens that characters overlap with pre-printed form lines. In order to recognize overlapped characters, removal of the line and restoration of the broken character strokes caused by line removal are generally conducted. But it is not easy to restore the broken character strokes accurately especially when the direction of the line and the character stroke are almost same. In this paper, a novel recognition method of line-touching characters without line removal is proposed in order to avoid the difficulty of the stroke restoration problem. A line-touching character is recognized as a whole by matching with reference character features which include a line feature. And the reference features are synthesized dynamically from a character feature and a line feature based on the touching condition of an input line-touching character string. We compared the performance of the proposed method with a conventional method in which a touching line is removed leaving the overlapped character stroke by mathematical morphology. Experimental results show that proposed method can achieves 96.26% character recognition rate whereas the conventional method achieves 92.77%.