Controlling the color appearance of objects by optimizing the illumination spectrum

TL;DR

This work addresses controlling color appearance of objects by optimizing the illumination spectrum to exploit metamerism rather than suppress it. The authors model illumination as a linear LED mix with $w_i = sum_k alpha_{i,k} e_k$ and compute object color via $v = C R w$, with metameric equivalence expressed as $CR_1 w = CR_2 w$. Two objective forms realize isochromatic and specific color-change effects under white-appearance constraints, selecting parameters such as delta and delta_white to balance color change with natural illumination. The approach was demonstrated at Paris Fashion Week 2024 using eight LED sets plus UV lighting, achieving measurable color changes in the $u'v'$ space and validating the intended metameric effects. These results suggest practical potential for design, advertising, inspection, and related applications across industries where controlled color perception is valuable.

Abstract

We have developed an innovative lighting system that changes specific target colors while keeping the lights appearing naturally white. By precisely controlling the spectral power distribution (SPD) of illumination and harnessing the unique phenomenon of metamerism, our system achieves unique color variations in ways you've never seen before. Our system calculates the optimal SPDs of illumination for given materials to intensively induce metamerism, and then synthesizes the illumination using various colors of LEDs. We successfully demonstrated the system's implementation at Paris Fashion Week 2024. As models step onto the stage, their dresses initiate a captivating transformation. Our system altering the colors of the dresses, showcasing an impressive transition from one stunning color to another.