Comparison of Edge Segmentation Methods to Tongue Diagnosis in Traditional Chinese Medicine

In Traditional Chinese Medicine, the human tongue is one of the important organs which contain the information of health status. In order to achieve an automatic tongue diagnostic system, an effective segmentation method for detecting the edge of tongue is very important. We mainly compare the Canny, Snake and threshold (Otsu's thresholding algorithm) methods for edge segmentation. The segmentation using Canny algorithm may produce many false edges after cutting; thus, it is not suitable for use. The Snake segmentation in tongue requires a larger convergence number and spends too much time. The threshold method using Otsu's thresholding algorithm and filtering process can achieve an easy, fast and effective segmentation result in tongue diagnosis. Therefore, it may be useful in clinical automated tongue diagnosis system.