Open Access
Development of a whiteness formula for surface colors under an arbitrary light source
Author(s) -
Wei Mao,
Siyuan Chen,
HsinPou Huang,
M. Ronnier Luo
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.018171
Subject(s) - chromatic adaptation , optics , light source , chromatic scale , adaptation (eye) , sample (material) , mathematics , surface (topology) , computer science , physics , geometry , thermodynamics
The whiteness specification is critically important in surface color industry, especially when fluorescent whitening agents (FWAs) are added to objects. The CIE whiteness formula, the most widely used whiteness formula, only characterizes the whiteness under CIE standard D65, which ignores the change of whiteness under different light sources due to the spectral content of the light sources. Though the adoption of a Chromatic Adaptation Transform (CAT02) in the CIE whiteness formula was found effective in recent studies, it failed to allow a comparison across different correlated color temperatures (CCTs). In this study, a haploscopic viewing condition was employed, with a D65 simulator in the left booth, for evaluating the whiteness of eight samples under different light sources in the right booth. The whiteness of the four samples under the D65 simulator was employed as a whiteness scale to aid the evaluation. Based on the experiment results, the characterization of whiteness for a surface under an arbitrary light source is proposed to use the CIE whiteness formula with the sample chromaticities being transformed using CAT02 and an adjusted degree of chromatic adaptation factor D.