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Colorcurve (D65/1964) and Coloroid (C/1931) notations of the 558 OSA-UCS atlas samples are presented in two tables. One table provides the Colorcurve and Coloroid notations for the 424 regular samples; the other for the 134 near-neutral (half-step) samples. Colorcurve notations are derived from the OSA-UCS aim points, and Coloroid notations are derived from colorimetric data of the OSA-UCS samples contained in MacAdam's copy of the OSA-UCS colour atlas.

This article presents an evaluation of the deviation of the Colorcurve atlas samples from their designated aim points. Sample deviations are evaluated in terms of hue, chroma, and lightness. In addition, the deviation of the Colorcurve samples from their respective aim points are graphically represented for eighteen lightness levels, Comparison is provided with NCS, DIN, and OSA-UCS atlas sample deviation.

Details of an expanded and improved computer program for the interconversion of colour notations are presented. This article describes the inclusion of the Colorcurve, SCA 2541, and HunterLab systems, expansion of the DIN and RAL implements, extension of the NCS aim point database, improvements to the OSA-UCS and Coloroid conversion algorithms, a direct spectral curve input facility, and the inclusion of CIELAB, CIELUV, HunterLab, CMC[1:1], FMC-1, and FMC-2 colourdifference formulas. © 1992 John Wiley & Sons, Inc.

NCS (C/1931) and DIN (C/1931 and D65/1964) notations of the 558 OSA-UCS atlas samples are presented in two tables. One table provides the NCS and DIN notations for the 424 regular samples; the other for the 134 near-neutral (half-step) samples.

This article describes a further investigation into the accuracy of the samples that comprise the NCS colour atlas. Earlier research has demonstrated that the NCS atlas samples are, on average, more inaccurate than the samples that comprise other comparable colour atlases. The present work identifies areas of the NCS colour atlas containing coloured samples that significantly deviate from their intended aim points.

A computer program has been developed that converts between the notations of the Munsell, OSA-UCS, NCS, DIN, and Coloroid colour order systems and the CIE, CIELAB, and CIELUV colour specification systems. The intention of this article is to outline the development of this program and its structure. Particular attention is given to the accuracy of the program and its associated databases.

In 1985 a research program was instigated to determine the feasibility and desirability of developing a computer based colour notation conversion program. Results indicated that the development of such a program covering the Munsel, NCS, DIN, OSA-UCS, Coloroid, CIELAB and CIELUV colour specification systems for use as a research tool was both feasible and desirable. The program was completed early in 1989 and this is the first of a number of articles that uses this program as a research tool. The colour notation conversion program has been used to evaluate the accuracy of the samples which comprise the NCS, DIN and OSA-UCS colour atlases.