Abstract

The spacing problem consists in the detection and correction of errors of allocation in surface-color space of the regular 1929 Munsell samples. This amounts to the adjustment of imperfections in a real chromatic skeleton of 400 units so that it will more properly fit into an ideal chromatic body. For the last five years various observers have been making visual estimates of the color spacings and the accumulated data have been summarized and are presented herewith in tabular form. These data will provide a psychological basis for defining smooth contours of Munsell hue, value, and chroma in terms of the 1931 I.C.I. colorimetric coordinate system. The plan is to present those contours in the final report. The present report includes charts of a preliminary smoothing of chroma based on the earlier visual estimates.

© 1940 Optical Society of America

Full Article  |  PDF Article

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1

The unsmoothed Glenn-Killian measurements of the 5/ value samples as plotted in four different colorimetric-coordinate systems.

Fig. 2
Fig. 2

Recording of estimates made by the simple ratio method.

Fig. 3
Fig. 3

Recording of estimates made by the difference ratio method.

Fig. 4
Fig. 4

Examples of Munsell constant-value charts and constant-hue charts mounted on white, gray, and black grounds; shown (A) without and (B) with several types of masks used to facilitate visual estimates by exposing simultaneously only samples designed to differ in a single attribute.

Fig. 5
Fig. 5

Examples of original forms for recording in vectorial notation visual estimates from a constant-value chart (left), and from a constant-hue chart (right).

Fig. 6
Fig. 6

Upper. Summarized visual estimates of hue and chroma of a particular Munsell sample (G 5/6) as presented on the three grounds. Lower. The corresponding numerical frequencies and averages.

Figs. 7–8
Figs. 7–8

Representative iso-chroma contours at value levels 2/ and 3/ based on preliminary visual estimates of the constant-value charts.

Figs. 9–10
Figs. 9–10

Representative iso-chroma contours at value levels 4/ and 5/ based on preliminary visual estimates of the constant-value charts.

Figs. 11–12
Figs. 11–12

Representative iso-chroma contours at value levels 6/ and 7/ based on preliminary visual estimates of the constant-value charts.

Figs. 13–14
Figs. 13–14

Representative iso-chroma contours at value levels 8/ and 9/ based on preliminary visual estimates of the constant-value charts.

Tables (2)

Tables Icon

Table I Average value determinations derived from the estimates of general value spacing, exclusive of the preliminary estimates. The observations were made for samples of each value on white, gray, and black grounds.

Tables Icon

Table II Average visual estimates of the 1929 Munsell samples as viewed on white, gray, and black grounds, together with the corresponding ranges of the central 80 percent of the estimates.

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

( C 2 / C 1 ) A = R A
( C 4 - C 3 / C 2 - C 1 ) = R A