title: Visual system-response functions and estimating reflectance.
abstract: The almost-illuminant-independent achromatic variable zeta [J. Opt. Soc. Am A 11, 1003 (1994)] is supplemented by two achromatic variables, both almost illuminant-independent. The results are numerically verified and obtained by means of so-called (human) visual system-response functions, defined as those linear combinations of the color-matching functions that constitute the best possible approximations to delta functions. It is argued that they and not the cone sensitivities are basic to understanding the visual system as a color-constant signal detection system. The three variables solve the color-constancy problem and define a chromatic adaptation transform for blackbody radiators of temperature T. The generalization of the results to arbitrary well-behaved illuminants is discussed.
authors.forename: C
authors.initials: C
authors.lastname: van Trigt
mesh_terms: D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008027:Light; D008433:Mathematics; D008962:Models, Theoretical; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012684:Sensory Thresholds