Open AccessHyperspectral environmental illumination maps: characterizing directional spectral variation in natural environments
Author(s) -
Takuma Morimoto,
Sho Kishigami,
João M. M. Linhares,
Sérgio Nascimento,
Hannah E. Smithson
Publication year - 2019
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.27.032277
Subject(s) - hyperspectral imaging , optics , remote sensing , variation (astronomy) , spectral imaging , computer science , geology , physics , astrophysics
Objects placed in real-world scenes receive incident light from every direction, and the spectral content of this light may vary from one direction to another. In computer graphics, environmental illumination is approximated using maps that specify illumination at a point as a function of incident angle. However, to-date, existing public databases of environmental illumination specify only three colour channels (RGB). We have captured a new set of 12 environmental illumination maps (eight outdoor scenes; four indoor scenes) using a hyperspectral imaging system with 33 spectral channels. The data reveal a striking directional variation of spectral distribution of lighting in natural environments. We discuss limitations of using daylight models to describe natural environmental illumination.