基于色度学的舌色分类研究现状与分析

目的探讨基于色度学的舌色分类研究现状,为数字舌图的舌色分类研究提供依据与参考。方法回顾性分析22项舌色分类研究的数据,将舌色的色度值统一转化为L值、a值、b值、C值、H值,进行各类舌色的色度值比较,并观察各类舌色在国际照明委员会(CIE)提出的颜色-对立空间模型(CIELAB)和明度彩度色调颜色模型(CIELCH)的分布,采用K均值聚类的方法,对不同研究者报道的舌色色度值进行聚类分析,并作色差比较。结果 22篇文章共报道了11类舌色:淡白舌、淡红舌、红舌、红绛舌、暗红舌、淡紫舌、紫红舌、青紫舌、紫舌、绛紫舌、紫暗舌。11类舌色的亮度在45～60之间,色相角在8°～27°和320°～355°之间,饱和度在17～36之间。从淡白舌到淡红舌、红舌、红绛舌、暗红舌,观察到有规律的色度值变化,表现为L值逐渐下降,而a值逐渐升高的趋势。以聚类中心位置的色度值为比较的基准,色差的范围在2.44～19.70之间。结论色度学为中医将舌诊的色觉经验进一步升华为量化色诊提供了关键的理论与技术。但不同研究者报道的色度值差异较大,也提示应当尽快制定数字舌图采集与色彩校正的规范方案与流程,使获得的舌色色度值能够在公共平台进行有效交流。

Current situation and analysis of classification study of tongue color based on colorimetry

Objective To discuss the current situation of classification study of tongue color based on colorimetry,and provide evidence and reference for the tongue color classification of digital tongue images.Methods The data from 22 studies on classification study of tongue color were analysed retrospectively,and colorimetric values of tongue color were converted unitedly into L value,a value,b value,C value and H value for comparing the colorimetric values of all types of tongue color and observing the distribution of color-opposition space model(CIELAB) and color model of luminosity and chroma hue(CIELCH) suggested by International Commission on Illumination.The colorimetric values of tongue color in different research reports were given clustering analysis and the aberration was compared by using K-means clustering method.Results There were totally 11 types of tongue color reported in 22 papers,and they were pale white tongue,pale red tongue,red tongue,crimson tongue,dark red tongue,lilac tougue,purplish red tongue,bluish purple tongue,purple tongue,crimson purple tongue,dark purple tongue.The brightness of 11 types of tongue color was from 46 to 60,hue angle was from 8 degree to 27 degree and from 320 degree to 355 degree,and saturation was from 17 to 36.There were regular laws in the changes of colorimetric values observed from pale white tongue to pale red tongue,red tongue,crimson tongue and dark red tongue,manifesting L value gradual decreasing and a value gradual increasing.The range of aberration was from 2.44 to 19.70 taken the colorimetric values in clustering central position as comparison datum.Conclusion Colorimetry supplies the key theory and technology for the transformation from TCM experience of color vision into quantification of color diagnosis.Because of big difference in colorimetric values reported by different researchers,the standardized plan and process should be made as soon as possible for collecting digital tongue images and correcting color and therefore,the obtained colorimetric values of tongue color can be communicated effectively on public platform.