Towards the objectification of tongue diagnosis: Automatic segmentation of tongue image

Tongue diagnosis is an important foundation of the syndrome difference. The segmentation of the body of tongue is a premise to establishing a system of automatic diagnosis by the feature of tongue in Traditional Chinese Medicine (TCM), whose qualities affect on the performance of tongue diagnosis. Because of similar color between tongue body and background, it is difficult to segment tongue. In order to overcome two key difficulties with the initialization and boundary concavities (important to the analysis of tooth´s marks), a novel method for tongue contour extraction based on improved level set curve evolution is proposed. We present an automatic initialization of contour by the feature of tongue in the HSV color space. Improved level set method takes not only color information but also tongue contour shape constraint represented by energy function between the evolving curve and parametric shape model. Applying our method to the large database of tongue images, we achieve promising experimental results.