A lighting system is proposed for acquiring color images under a variety of illuminations. This system is constructed with halogen lamps, color filters, white diffusion filters, dimmers, and a personal computer as a controller. Colored light with continuous spectral power distribution is generated based on the additive color mixture of RGB primary lights. First, we describe a method for generating light of a desired color stimulus value. The basic procedure is performed in two steps: (1) XYZ-RGB color coordinate conversion and (2) correction of nonlinearities. A practical procedure is presented for generating colored light with (x,y) chromaticity coordinates of any value within a specified color gamut.
Shoji Tominaga, Shoji Tominaga,
"Lighting system for color images", Proc. SPIE 3963, Color Imaging: Device-Independent Color, Color Hardcopy, and Graphic Arts V, (21 December 1999); doi: 10.1117/12.373397; https://doi.org/10.1117/12.373397