An Experiment in Visual Scaling of Small Color Differences*

TLDR

An ISCC Committee experiment examined visual scaling of small color differences in six color microspaces. Researchers evaluated object‑color samples through ranking, subjective estimation, and acceptability judgments, computed visual scales via traditional methods, and correlated them with CIELAB, C1ELUV, FMC‑2, and FCM formulas, optimizing ellipsoids to the data. The study found no fundamental difference between perceptibility and acceptability judgments and achieved higher correlations between visual and calculated color differences than previous comparable experiments.

Abstract

Under the auspices of the ISCC Committee on Color Difference Problems, an experiment was carried out in the visual scaling of small color differences involving six color microspaces. The object‐color samples were visually evaluated by ranking, by subjective estimation, and by acceptability judgments. Visual scales were calculated by traditional procedures. Correlations were calculated between the visual scales and four color‐difference formulas (CIELAB, C1ELUV, FMC‐2, and FCM), and ellipsoids were optimized to the visual data. No fundamental differences were found between the results of the perceptibility judgments and the acceptability judgments. Higher correlations than reported for earlier comparable experiments were obtained between visual and calculated color differences.