Analysis of pigmentation in human skin: quantification of ultraviolet ray images by digital image processing

Synopsis A new method for quantifying pigmentation with transformation of ultraviolet ray images into digital images has been developed. Utilizing this method, the distribution of pigments deposited in healthy Japanese subjects has been investigated. The following characteristics of pigmentations have now been obtained as follows: - the amount of total pigmentation areas and the frequency of appearance of large pigmented areas increase with ageing; - in young and middle age groups, women have more pigmentation than men, whereas in old age, this trend is reversed; - the amount of pigmentation is greatest on the front of the cheeks and the least on the forehead; - pigmentation areas darken in summer, and the amount of pigmentation and number of pigmented areas increase in summer. Interestingly enough, a correlation between 'ultraviolet rays in daily life' and 'the pigmentation in human skin' is strongly suggested.