Page:Tristimulus specification of the Munsell book of color from spectrophotometric measurements (IA jresv31n1p55).pdf/6



Values of X, Y, Z, x, and y for all of the samples and for the four illuminants, as explained above, together with the Munsell notations, 'H V/C (hue, value, and chroma), and the Munsell painting number for each sample, are given in table 2. Values for the neutrals are at the end of the table. Values of z are omitted, since z=1-x-y.

Values of the trilinear coordinates, x and y, for ICI illuminant C, are plotted in figures 2 to 8 for Munsell values 2 to 8, respectively. The x and y values for 101 illuminant C, and therefore for magnesium oxide and for any other spectrally nonselective sample, are given in each diagram at x=0.3101, y=0.3163. Values of x and y for the Munsell samples obtained at the National Bureau of Standards are plotted as circled points. The data obtained by Glenn and Killian [8] at the Massachusetts Institute of Technology in 1935 are plotted as uncircled points for comparison with the present data. When the two points for a sample coincide, the combination is plotted, as a circled point with a short line attached; in many cases, to avoid confusion, the two points are joined by a fine line. Lines are drawn connecting all of the NBS points of constant chroma on each diagram, resulting in the spiderweb-like figures shown.