Skin color is one of the most obvious features of the skin. Various information can extracted from the analysis of skin color, including age and health. The necessity of skin color measurement extends from clinical dermatology to aesthetic cosmetology, which means that an objective and reproducible measurement of skin color would be of significant value. However, conventional measurement methods using pressed devices are associated with limitations, included small areas can be measured and the potential for contact power to cause errors. In this study, we performed skin color measurement utilizing the individual typology angle (ITA) and hue angle, indexes that are calculated from digital images with specific algorithms. Ninety-one healthy Japanese female subjects of 18—60 years of age were recruited for this study. The facial ITA and hue angle of three anatomical sites (forehead, cheek and jaw) were collected using the re-Beau^® and CR-13. The spectral characteristics of white LED lamps were confirmed before measurement. Our analysis showed that the ITA was highest in the forehead and lowest in the jaw, with significant differences from the values at other locations. The hue angle measured on images was lower than that measured by colorimeter. In conclusion, the present study describes the application of a skin color measurement imaging method using the ITA and hue angle. This method may be applied in the skin color related dermatosis diagnosis support system in which the individual typology angle (ITA) is used to evaluate pigmentation and the hue angle is used to identify erythema.

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