A new algorithm for calculating the MacAdam limits for any luminance factor, hue angle and illuminant

Abstract

The MacAdam limits are the frontier of the human colour solid in any colour space. The colour stimuli associated with this frontier are the optimal colours studied by D.L. MacAdam in 1935. Since then, the optimal colours have been calculated and plotted in several CIE colour spaces only under the A, C, D65 and E illuminants with a limited range of the luminance factor Y (typically, from 10 to 95 % at 10 % steps). We show a new algorithm for systematically searching the optimal colours for any illuminant (F2, F7, F11, etc) and luminance factor (between 0 and 100 %). With these chromatic data we can graph the colour solid in CIELAB colour space at constant lightness and hue angle planes for any illuminant or even light source.