Understanding how light interacts with skin, can assist in designing physics based dermatological image processing. The key is to understand how light interacts with skin tissue. Skin consists of different layers with different spectral properties.
When incident light is applied to skin layer, the part of it absorbed and other part is scattered. The main layers of skin are as follows: Stratum cornea it practically doesn’t absorb light, but diffuses it; Epidermis consists of cells producing pigment melanin. Melanin strongly absorbs strongly absorbs light wavelengths towards ultraviolet part; Dermis is next skin layer which consists of collagen fibers. It can be split in to two sub layers: Papillary dermis and dermis itself. Papillary dermis consists of high dense of collagen fibbers who are strong scattereer of light. The main model requirement is that light has to be scattered. Stratum cornea is supposed as scattering filter. Skin can be characterized as follows:
1) Epidermis, depending on wavelength can be characterized with melanin absorption coefficient μamam(λ) and melanin concentration cm;
2) ed with hemoglobin absorption coefficient μah(λ), hemoglobin concentratμah ch, collagen scattering coefficient μspd and collagen layer thickμspd dpd;
3) Dermis can be ddpdribed with scattering coefficient μsrd and thickness of layer dμsrd
Using those parameters drd model of skin was calculated which shows reflected light dependency on skin parameters and wavelengths of light:
This color surface shows all awailable skin color values available. This color surface includes all races, sunburn degrees or even age. All benign lessions where melanin is only in epidermal layer also implies to this surface.