Method of tongue image segmentation based on luminance and roughness information

Tongue image segmentation is the first important step of tongue diagnosis digitization. To segment tongue from image efficiently, a method based on luminance and roughness was proposed. First the Otsu method was implemented to select a threshold in luminance field of the image automatically. Then, non-tongue regions were eliminated with the difference between the roughness of tongue and skin. Finally, ultimate result was produced by employment of erosion, dilation and opening operation in mathematical morphology. The experimental result shows that this method is significant and efficient.