Text-line extraction and character recognition of Japanese newspaper headlines with graphical designs

The conventional OCR fails to recognize most characters in Japanese newspaper headlines with graphical designs because of the difficulty of removing the designs. This paper proposes a method that recognizes such characters without removing the designs. First, text-line regions are extracted from a local distribution of the combination of black and white runs observed in a rectangular window while the window is shifted pixel-by-pixel in the direction of the text-line. Characters in the extracted text-line region are then recognized by displacement matching. Adaptive thresholding against the degree of degradation suppresses spurious candidates yielded by displacement matching even with graphical designs. Experimental results for fifty Japanese newspaper headlines show that the method achieves a recognition rate of 97.7%, much higher than a conventional method (17.0%).