An Innovative Method to Measure Skin Pigmentation

Abstract

It is crucial to develop accurate measuring method for skin pigmentation in preparation of effective whitening agents or cosmetics. We developed a system, it is called REMO-STAIN system, by which we were able to measure the stain at any part and in any area of face. However, this system was slightly influenced by pimples and redness of face because stains were selected using the color difference (ΔE) between stain and around normal areas. We have developed the method to calculate the concentration of melanin and hemoglobin from skin reflection spectrum using multiple regression analysis, assuming that Lambert-Beer's law is applicable to skin reflection spectrum among 500-700nm and that the absorption spectra of skin is expressed as linear summation of melanin in epidermis, hemoglobin in vessel blood and absorption in dermis. We applied this method to REMO-STAIN system to develop a new system to estimate skin pigmentation quantitatively without influence of pimples and reddish face. This new REMO-STAIN system can measure the melanin and hemoglobin contents at each pixel in CCD images of the face and calculate the area of pigmentation in the facial skin. So, new REMO-STAIN system seems to be very useful in the efficacy test of depigmentation products.