Study of Analysis and Quantitative Estimation of Melanin in Face Epidermal Corneocyte

In medical and cosmetic fields, skin color and texture have not been investigated quantitatively so far despite of the importance. Ordinarily, melanin is produced increasingly due to excessive stimulus such as ultraviolet rays, and excessive melanin causes pigmentation such as spots and freckles. Therefore, since melanin pigmentation is one of the important barometers to express skin color and texture, we focus on estimating quantity and uniformity of melanin in corneocyte for quantitative analysis of skin texture. Extraction methods of melanin by image processing have been developed and then quantitative indices obtained through image processing have been proposed. By using multiple linear regression analysis, we find that visual appreciation score about quantity and uniformity of melanin by human expert is highly predictable by using these quantitative indices. Though human expert takes much time to score, proposed method is able to shorten the amount of time remarkably, and it comes into practical use since June 2010.