Joint Method of Interference Suppression and Super-Resolution for Chinese Characters Image with Interference

Abstract

As Chinese characters image often has insufficient photography illumination, or underlines under characters, or low resolution, a joint method of interference suppression and super-resolution for Chinese characters image with interference is proposed. In the stage of interference suppression preprocessing, the technology of image layer separation is used to decompose Chinese characters image into the illumination layer and reflectance layer at first, and reflectance layer that contains the essential property of input image is retained consequently. Then the reflectance layer is decomposed into four coefficient subimages by wavelet transform, and image smoothing via L0 gradient minimization with different scale factors is adopted to these different coefficient subimages. Subsequently, by a simple background processing and image filtering, the image preprocessing for Chinese characters image with interference is ultimately completed. In the stage of image super-resolution, due to acquisition limitation of a large number of high-resolution Chinese characters images, we adopt neighbor embedding super-resolution method for its advantage of greatly reducing the scale of training set. In the key feature vector of Chinese characters image, the weights of horizontal and vertical stroke features are strengthened; meanwhile, the other stroke features of Chinese characters are also considered. Ultimately, a super-resolution method more suitable for Chinese characters image is proposed. Experimental results show that our method of interference suppression has the superiority for Chinese characters images with aforementioned interference, and our optimized super-resolution method has better performance for test Chinese characters images than bicubic interpolation method and three classical super-resolution methods.