Independent-component analysis of skin color image.

The spatial distributions of melanin and hemoglobin in human skin are separated by independent-component analysis of a skin color image. The analysis is based on the skin color model with three assumptions: (1) Spatial variation of color in the skin is caused by two pigments, melanin and hemoglobin; (2) the quantities of the two pigments are mutually independent spatially; and (3) linearity holds among the quantities and the observed color signals in the optical density domain. The results of the separation agree well with physiological knowledge. The separated components are synthesized to simulate the various facial color images by changing the quantities of the two separated pigments.