Dichromatic reflectance model

In Shafer's dichromatic reflection model,^[1] scene radiance has two components:

${\displaystyle L(\lambda )=m_{\mathrm {b} }c_{\mathrm {b} }(\lambda )+m_{\mathrm {s} }c_{\mathrm {s} }(\lambda )}$

λ is the wavelength,

c_b is the body (diffuse) reflected component,

c_s is the surface (interface) (specular) reflected component,

m_b and m_s are scale factors depending on illumination, view directions and surface orientation.

Separation algorithm

BREN (body reflection essence-neuter) model based

Body essence is an entity invariant to interface reflection, and has two degrees of freedom. The Gaussian coefficient generalizes a conventional simple thresholding scheme, and it provides detailed use of body color similarity.^[2]