Patent ID: 7523018

Claim:
A system for determining hair color treatment, comprising: a processor configured for: (i) receiving as input an initial reflectance spectrum of a sample of hair, said initial reflectance spectrum comprising a plurality of reflectivities at wavelengths over a wavelength range, said reflectivities being accumulated together to form said spectrum; (ii) from said initial reflectance spectrum calculating a new reflectance spectrum for said hair due to a hypothetical hair color treatment, said hair color treatment comprising a first hair color treatment associated with a first relative concentration and a first spectral change function and comprising bleaching, and a second color treatment associated with a second relative concentration, and a second spectral change function and comprising dyeing, said calculating comprising using a spectral multiplication function of said initial spectrum, said calculating comprising considering the effect of treatment on reflectivities at individual wavelengths in said initial reflectance spectrum and accumulating said reflectivities to form said new reflectance spectrum, said calculating comprising apportioning of the first and second spectral change functions according to the first and second relative concentrations; and (iii) outputting said new reflectance spectrum to a device, thereby to indicate a likely result of applying said hypothetical hair color treatment to said sample of hair.