Chromatic Strengthと知覚白色度の関係

Abstract

Using psychological experiments, we investigated the perceived whiteness of a white object under 30 types of illuminants. We used the index we developed in an initial study [J. Illum. Inst. Jpn. Vol.83 No.11 (1999)] and modified in a subsequent study [J. Illum. Inst. Jpn. Vol.85 No.5 (2001)] to evaluate the perceived whiteness. The index is proportional to the total chromatic strength of the spectral stimulus at a constant luminance level; it correlated highly with the experimental results, indicating that it can be used to effectively evaluate the perceived whiteness of a white object under various illuminants.Considering the ability of a spectral stimulus to induce brightness and chromatic perception, we investigated the cause of whiteness perception. We found that whiteness perception, the Helmholtz-Kohlrausch effect, the discrimination threshold level of colorimetric purity, and the G0 function studied by Evans are all caused by a basically common color perception mechanism and that they can be explained uniformly by using chromatic strength.