Colorimetric Study on Tongue Color in Chinese Medicine Tongue Inspection by Visible Reflection Spectrum
应用可见反射光谱法对中医舌诊舌色的色度学研究

In this study, a visible reflection spectrum system was used to collect data of tongue tip color. The calculation of chromaticity coordinate parameters and translation to RGB color space of tongue tip color data were also carried out. The CIE 1931 XYZ tristimulus values of tongue tip color from 120 subjects were calculated on the basis of visible reflection spectrum. And the CIE xy chromaticity diagram distribution of tongue tip color among 120 subjects was also obtained. Meanwhile, the RGB color space parameters of the tongue tip color among 120 subjects were translated by the XYZ tristimulus values. The results showed that differences of tongue tip color among different samples can be observed obviously while the optical data on color of tongue tips was cited in CIE 1931 chromaticity diagram. The CIE 1931 XYZ tristimulus values can be translated into RGB color space parameters of the tongue tip color among 120 subjects. Furthermore, there was the phenomenon of different optical spectrum for the same color in the tongue inspection. It was concluded that based on the collection of the information data of tongue tip color with visible spectrum from 380 nm to 780 nm, the calculation of chromaticity coordinate parameters and translation to RGB color space of tongue tip color data can be feasible in a high refutation and reproducibility.It provided a useful assistance for investigating the phenomenon of different optical spectrum for the same color in the tongue inspection of traditional Chinese medicine.