关键词: 麻将图像, 光照不均, 图像锐化, 色度分量, 局部去噪

Abstract: To solve the uneven illumination of mahjong image for the visual detection of mahjong arrayal, an adaptive correction method of mahjong image based on the feature classification is proposed. Firstly, according to the feature analysis of mahjong’s arrangement, the background subtraction and projection methods are used to segment the whole mahjong image from the capture image. Secondly, the whole mahjong is divided into single mahjong, which is further divided into three types：highlight mahjong, shadow mahjong and uniform mahjong by the feature analysis of illumination. Thirdly, mean normalization is performed for the highlight mahjong and shadow mahjong. Fourthly, the whole mahjong image is sharpened, and its characteristics are strengthened by using the chrominance component. Finally, it uses the local method of analyzing the amplitude around to remove the noise of the shadow mahjong based on the feature of the noise. Experimental results show that the proposed method has better correction for the uneven illumination of mahjong image than state-of-art methods and can improve the recognition rate effectively for the mahjong arrayal detection.

Key words: mahjong image, uneven illumination, sharpening, chrominance, local denoising