AUTHOR=Koenderink Jan , van Doorn Andrea , Gegenfurtner Karl TITLE=RGB Colors and Ecological Optics JOURNAL=Frontiers in Computer Science VOLUME=3 YEAR=2021 URL=https://www.frontiersin.org/journals/computer-science/articles/10.3389/fcomp.2021.630370 DOI=10.3389/fcomp.2021.630370 ISSN=2624-9898 ABSTRACT=

Object color space is highly structured due to optical constraints (radiant power non-negative, reflectance factors between zero and unity) and ecological context (daylight illuminant). In this setting trichromacy induces a natural geometry through a unique spectral tripartition. Different from null-context colorimetry, one gains two desirable relations: The colorimetric coordinates are coarse-grained spectral reflectance factors and there is a direct link to color experiences, since RGB–coordinates provide ostensive definitions. The framework allows one to deal with subtractive color mixture, source variation, effects of metamerism and relations between scenes and image data in a unified, structured manner. In ecological contexts, colors are effectively object properties. The formal framework is linear algebra and convex geometry. Applications in human biology, computer graphics, design, etc., are immediate.