The Color of The Skin and its Spectral Reflectance as a Function of Correlated Tristimulus Values

Abstract

Spectrophotomeric measurements on the colors of japanese women's skins ranging from 19 to 47 years of age were carried out by means of the Hitachi Color Analyzer Model 607.The color of each subject's skin was measured after the removal of any make-up.(1) The average colors of the skins (forehead, cheek and lower lip) in Munsell renotation system were 3.5 YR 6.0/3.8, 1.6 YR 6.3/3.9, 7.6 R 5.5/4.3, res pectively.(2) A principal component analysis was made on the spectral reflectances of the skins; it was found that by the first three principal components, the variances of the spectral reflectances on the colors of the foreheads, the cheeks and the lower lips were explained at 98.1%, 97.2%, 98.0%, respectively.(3) From the mean of the spectral refletances of the skins and their first three characteristic vectors, the spectral reflectance curves were reconstituted by the scalar multiples of the characteristic vectors as a function of correlated tristimulus values.The figure of the reconstituted spectral reflectance curves was compared with the curve obtained by the practical measurement at the same tristimulus values.They have shown good agreement.(4) The spectral reflectance curves of the metameric colors on the skins, in which a corresponding tristimulus values are the same but the spectral compositions are different, were reconstituted by the liner combination of the first sixth characteristic vectors and the mean spectral reflectance.