A simple method to estimate CIE-L*a*b* values of the skin from its videomicroscopic image

The C I E (Commission Internationale de I'Eclairage)-L*a*b* is the most popular standardized color system. The purpose of this study was to develop a simple method for estimating C I E-L*a*b* values of the skin using a video microscope and a computer.

Skin images were obtained with a video microscope of various anatomical locations and ultraviolet B-induced erythema and pigmentation in seven subjects. R G B (red, green, and blue) color coordinates of the images were converted into quasi-L*a*b* values using formulae similar to those defined by C I E. These values were compared with C I E-L*a*b* values simultaneously measured with a colorimeter.

The correlation coefficients between C I E- and quasi-L*a*b* values were 0.97 (L*), 0.91 (a*), and 0.84 (b*

Our method may be useful for deriving CIE-L*a*b* values of the skin from its video microscopic image.