“TOUMEIKAN” is important subject of human skin, or painting of it. Several techniques of make-up items representing “TOUMEIKAN” were proposed. Such as transmitting red light, reflecting blue light, making uniform, and putting a gloss. In this study, we aimed establishing new approach representing “TOUMEIKAN”, and focused the perception of multi-layer structure, that was found by a painting technique of human skin. Then, we tried to clarify the mechanism of this perception and developed the evaluation method. As a result, we found that the perception of multi-layer structure was caused by the gap of standard deviations of bands resolved by multiresolution analysis, and we could evaluate this perception using the index value showing the depth of this gap.
Some previous surveys reveal that the facial skin color of Japanese women varies across the ages. Compared with that in the early 1990s, the lightness of the skin color of Japanese women in the early 2000s is confirmed to increase. However, in the decades after 2000, changes in facial skin color have been hardly investigated by evaluating them quantitatively.
The aim of this study was to investigate change in the facial skin color of Japanese women for 25 years by analyzing difference in skin reflectance measured with three different types of spectrophotometers. Firstly, the skin color on a specific part of a face was measured with different spectrophotometers, and a correction equation was established for comparing the skin color data by confirming difference in the output spectral reflectance.
Next, the cheek skin colors of approximately 2,000 Japanese women were measured in 2005 and 2015, and the data were compared with corrected 1991 data, and 2001 data. The results showed that the skin color of Japanese women shifted to lower chroma and become reddish since 2000.