Age Effects on Observer Metamerism

Abstract

Studies on observer metamerism reported so far are classified into two groups; one is studied by G. Wyszecki, E. Allen, and Y. Nayatani et al based on the Stiles's 20 color-matching functions, and the other by P. K. Kaiser et al and F. W. Billmeyer et al on the basis of color-matching assessments on the Davidson and Hemmendinger color rule. It has been suggested that a large difference exists between the two series of studies on a ratio of observer metamerism index to illuminant metamerism index. This difference is analyzed by using the Stiles's 20 color-matching functions and the color-rule samples.
The results are; (1) the ratio of age effect on observer metamerism to illuminant metamerism index estimated by the Stiles's 20 observers are very similar to that given by P.K. Kaiser et al., (2) the large difference between the two study series stated above is partly caused by the computational procedure used for deriving each observer-metamerism index, and (3) the Stiles's 20 observers are a good representative of color-normal observers covering a wide range of age from ahniit 20 to about 60.