title: Angle resolved color of bulk scattering media.
abstract: The angle resolved reflectance factor of matte samples is measured with a                 goniophotometer and simulated using radiative transfer theory. Both measurements and                 simulations display the same characteristic dependence of the reflectance factor on                 the observation angle. The angle resolved reflectance spectra are translated to                 CIELAB color coordinates and the angular color differences are found to be                 surprisingly large. A chromatic adaptation that is dependent on the observation                 angle is suggested, in which a nonabsorbing opaque medium is used as the reference                 white, and the angular color differences are then reduced. Furthermore, the use of                 an undyed paper as the reference white is evaluated. The angular lightness                 differences are then reduced further, but the angular differences in chroma are                 still large. It is suggested that smaller variations in perceived color could be                 explained by angle dependent chromatic adaptation and a limited sensitivity of the                 human visual system to changes in chroma.
authors.affiliation: Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Härnösand, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Neuman
authors.forename: Ludovic G
authors.initials: LG
authors.lastname: Coppel
authors.forename: Per
authors.initials: P
authors.lastname: Edström