White balance with reference illuminants

Introduced here are computer programs and associated computer-implemented techniques for achieving high-fidelity color reproduction in the absence of any known reflectance spectrums. That is, high-fidelity color reproduction can be achieved without portable references, such as gray cards and color checkers. To accomplish this, a new reference spectrum-the "reference illuminant spectrum"-is introduced into scenes to be imaged by image sensors. The reference illuminant spectrum is created by a multi-channel light source whose spectral properties are known.