Skin Colour Imaging that is Insensitive to Lighting Conditions

In previous human skin models, it has been suggested that the colour of human skin is mostly determined by the concentration of melanin in the epidermal layer combined with the concentration of hemoglobin in the dermal layer. The colour of facial skin changes significantly with changes in the light incident upon it. In this paper we propose a method of normalizing the skin tones of human faces that eliminates the effects of illumination, preserving the skin colour and allowing variations related to melanin concentration only. The method assumes the illumination is reasonably well modelled as blackbody radiation.