An approach to preprocess degraded text images based on morphological filters
Hongwei Kong, Liangrui Peng, Xiaoqing Ding · 2002
The recognition rate of OCR (optical character recognition) systems often decreases for degraded text images, such as stroke-connected, stroke-broken and noisy text images. In this paper a unified method for preprocessing binary text images based on mathematical morphology is presented. Simple but effective morphological filters are designed to process stroke-connected and stroke-broken images separately. A method to classify stroke-connected and stroke-broken text images based on the horizontal and vertical average stroke width is also presented. A morphological contour filter is used for removing noise. Experimental results show that the result of the preprocessing method are satisfactory.