Abstract
A multidimensional ratio-scaling method was used to analyze one observer’s color difference judgments made on two sets of colored tiles of equal luminous reflectance. The precision of the observed color differences was found to be approximately ±30%. Taking this precision into account, the analysis indicated that all colors could be represented by points in a two-dimensional Euclidean space in which distances between two points were proportional to observed color differences independent of the location of the points. A method involving relatively simple computations is used to derive the perceptual space for a large group of colors by dividing the group into several subgroups and then overlapping the scaling solutions obtained for each subgroup.