Surface appearance, apart from texture, is defined by the goniophotometric curve giving the angular distribution of the reflected light. A summary of current goniophotometric techniques shows that essential parts of these fundamental data have been neglected. This paper applies an established method of statistics to the problem of goniophotometric-curve analysis and interpretation whereby such data are reduced to dispersion, skewness, and kurtosis indexes. The kurtosis index is shown to correlate better with subjective estimates of the distinctness of the reflected images than the conventional measure, 60° specular gloss. The kurtosis index is applied to one problem in the selection of optimum glossmeter geometry.
I. NIMEROFF, "Analysis of Goniophotometric Reflection Curves," J. Opt. Soc. Am. 42, 579-582 (1952)