Color Constancy from Invariant Wavelength Ratios: An Algorithm to Simplify the Chromatic Adaptation Model

In a recent article on color constancy, the chromatic adaptation model was of a novel type comprising three components separately calculated-hue, chromaticness, and lightness. The constant hue component was a simple calculation of predicted wavelength but the other two components were less direct. This article provides an algorithm to simplify the model's calculation. Calculation is far simpler and more intuitive than conventional models using complex 3 3 3 matrix transforms with their various and contentious adaptation primaries and potential disadvantages (e.g., in brightness and color gamut). The model is shown to be at least as accurate as six other (conventional) models and does not require high math skill. (C) 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 468-476, 2016; Published Online 28 June 2015 in Wiley Online Library (wileyonlinelibrary.com).