A novel automatic tongue image segmentation algorithm: Color enhancement method based on L*a*b* color space

As the first step of tongue image analysis, tongue segmentation plays a significant role in this field. In this paper, we present a new method to segment the tongue using multiple color spaces. Based on the hue channel in HSV space, a threshold control function can be given, revealing the chromatic feature of image. Then we can extract our interested area according to the function, so that the color enhancement method can be applied in this region. In the end, we can obtain the complete outlines using the luminance features in L*a*b color space. Compared to existing tongue segmentation algorithms, our method demonstrates satisfying performance in robustness, efficiency and accuracy.