How many surfaces can you distinguish by color? Real environmental lighting increases discriminability of surface colors

Morimoto T., Linhares JMM., Nascimento SMC., Smithson HE.

Color supports object identification. However, two objects that differ in color under one light can appear indiscriminable under a second light, a phenomenon known as illuminant metamerism. Past studies evaluated the frequency of illuminant metamerism only under single, uniform illuminants. Here we used computer-graphics techniques to simulate a pair of planar surfaces placed under newly measured hyperspectral illumination maps that quantify the directional variability of real-world lighting environments. We counted the instances of illuminant metamerism that can be solved simply by viewing surfaces tilted to a different direction. Results show that most instances of illuminant metamerism can in theory be resolved for both trichromatic and dichromatic observers, suggesting that the physical directional variability available in natural lighting environments substantially mitigates the biological limitations of trichromacy or dichromacy.

DOI

10.1364/oe.531468

Type

Journal article

Journal

Optics Express

Publisher

Optica Publishing Group

Publication Date

23/09/2024

Volume

32

Pages

34246 - 34246

Permalink Original publication