The effect of dividing-strip width (sample proximity) upon sensitivity to suprathreshold and threshold color differences is explored by three methods that involve ratio comparisons, liminal determinations, and repeated color matchings. The results suggest, in general, that sample separation impairs lightness discrimination more than chromaticness discrimination and that it may be necessary to introduce a proximity factor into color-difference formulas when evaluating threshold or small-size color differences.
© 1976 Optical Society of America
L. T. Sharpe and Gunter Wyszecki, "Proximity factor in color-difference evaluations," J. Opt. Soc. Am. 66, 40-49 (1976)