基于非参数密度估计对烤烟烟叶颜色CIE1976（L^＊a^＊b^＊）色空间的三维空间图的研究

Research on Three -dimensional Spatial Diagram for CIE 1976 （L^＊a^＊b^＊） Color Space of Flue - cured Tobacco Leaf Color Based on Non - parametric Density Estimate

利用色差仪对云南9个烟区K326烤烟品种,3个部位的烟叶进行了颜色指标的测定。应用CIE 1976(L*a*b*)色空间理论,采用非参数密度估计函数,对颜色数据做非参数密度估计图,并以颜色的3个指标L、a*b*,分别作三维空间的坐标轴Z轴、X轴、Y轴,绘制了三维山峰图和等值线图。结果表明,通过三维图能够清晰地表征出3个部位的空间层次分布,通过山峰图能有空间立体层次地表现颜色指标,通过等值线图能看出每个部位颜色数据的分布情况,解决了颜色3个指标来表征一个特性的情况,可为今后颜色指标的数据库建立提供一定的基础。

In 9 tobacco - planting areas of Yunnan province, the color indicators of 3 parts of flue - cured tobacco variety K326 were measured by color difference instrument. CIE 1976 （L^＊a^＊b^＊）color space theory and nonparametric density estimate function were used to make nonparametric density estimation diagram of color data. Three indicators of color L, a^ ＊ , b^ ＊ were separately taken as the Z, X, Y coordinate axis of the three - dimensional space, and the three - dimensional peak image and contour map were drawn. The results showed that the three - dimensional peak image could clearly characterize the spatial and stepwise distribu-tions of the three parts and color indicators. Contour map could understand the distributive conditions of color data every part, which solved a problem that three color indicators could only express a character. Therefore, it can provide a certain basis for establishing color indicator database in the future.