Study of Skin Color Unevenness Using Independent Component Analysis

Abstract

Skin color unevenness, such as age spots, freckles and acne, accounts for the majority of skin trouble in Japanese females, and has been becoming an important research subject in the field of both cosmetics and beauty healthcare. We analyzed the melanin unevenness in the faces of 201 Japanese females in their teens to 70s using independent component analysis, which can separate an original color image into a melanin component image and a hemoglobin component image. As a result, we discovered that thin and vague border melanin unevenness, which differs from age spots, spreads into the skins. We also found out that the age change of “vague border melanin unevenness” became more conspicuous in the cheeks, and spread over the facial skin from upper cheek to lower cheek with aging. Furthermore, we found a high correlation between “vague border melanin unevenness” and “skin dullness”, which is a skin trouble specific to middle-aged females. From the above findings, we conclude that “vague border melanin unevenness” is appropriate as the new evaluation index of “skin dullness”, and is useful for the effectiveness evaluation of whitening products.