Abstract

Friele proposed formulas by which color metric coefficients can be computed. Values thus computed were used to evaluate a large number of uniformly distributed unit color differences, as gauged by color-matching results. The mean-square deviations from unity of the evaluations were used to study the effects of changing the parameters published by Friele. Optimum parameters were determined for each of two sets of experimental data. For each set of data, parameters were determined for equiluminous test colors and also for the general case. All four determinations were repeated with a modification Friele suggested for his formulas. The greatest reductions of mean-square deviations resulted from changing the green primary assumed by Friele. In all cases, the optimum green primaries were found to be in the upper left-hand quadrant of the CIE chromaticity diagram. With the optimum green primaries and parameters, the mean-square deviations were reduced to about half of those obtained with the Friele primaries and parameters. Friele’s modification of his formulas did not improve these results.

© 1964 Optical Society of America

Analytical Approximations for Color Metric Coefficients. IV. Smoothed Modifications of Friele’s Formulas*

David L. MacAdam
J. Opt. Soc. Am. 55(1) 91-95 (1965)

Analytical Approximations for Color Metric Coefficients. II. Friele Approximation

David L. MacAdam
J. Opt. Soc. Am. 54(2) 249-256 (1964)

Optimization of the MacAdam-Modified 1965 Friele Color-Difference Formula

K. D. Chickering
J. Opt. Soc. Am. 57(4) 537-541 (1967)

Friele Approximations for Color Metric Coefficients

L. F. C. Friele
J. Opt. Soc. Am. 56(2) 259_1-260 (1966)

FMC Color-Difference Formulas: Clarification Concerning Usage

K. D. Chickering
J. Opt. Soc. Am. 61(1) 118-122 (1971)