Method of simply setting expansion regions for conversion of values of colors according to xyz notation system into values of colors according to Munsell notation system

摘要

A method of expanding the regions in which conversion of color values in the CIE notation system to values in the Munsell notation system can be made. On a conventional Munsell chromaticity diagram having equi-hue lines and equi-chroma loci and superimposed on a CIE set of coordinates in a conventional conversion diagram, the respective equi-hue lines are extended outwardly from the outermost equi-chroma locus in a direction in alignment with respective lines connecting the respective intersections of the outermost equi-chroma locus with the respective equi- hue lines and the intersections of the next inward equi-chroma locus with the respective equi-hue lines, the extension being to points along the extended equi-hue lines which are integral multiples of a value d which is equal to {square root}(x.sub.1 -x.sub.2).sup.2 +(y.sub.1 -y.sub.2).sup. 2 where x.sub.1 and y.sub.1 are the CIE notation values of the points of intersection of the respective equi-hue lines and the outermost equi- chroma locus, and x.sub.2 and y.sub.2 are the CIE notation values of the points of intersection of the respective equi-hue lines and the next inward equi-chroma locus. The points along the extended equi-hue lines are joined with corresponding points on adjacent equi-hue lines to form further equi-chroma loci outwardly of the outermost equi-chroma locus.