Visual Evaluation at Scale of Threshold to Suprathreshold Color Difference

摘要

Visual evaluation experiments of color discrimination threshold and supra threshold color-difference comparison were carried out using CRT colors based on the psychophysical methods of interleaved staircase and constant stimuli, respectively. A large set of experimental data was generated ranged from threshold to large supra threshold color difference at the five CIE color centers. The visual data were analyzed in detail for every observer at eachvisual scale to show the effect of color-difference magnitude on the observer precision. The chromaticity ellipses from this study were compared with four previous published data, of CRT colors by Cul and Luo, and of surface colors by RIT-DuPont, Cheung and Rigg, and Guan and Luo, to raport the reproducibility of this kind of experiment usingCRT colors and the variations between CRT and surface data, respectively. The present threshold data were alsocompared against the different suprathreshold data to show the effect of color-difference scales. The visual results were further used to test the three advance color-difference formulae, CMC, CIE94, and CIEDE2000, together with thebasic CIELAB equation. In their original forms or with Optimized K_L values, the CIEDE2000 outperformed others,followed by CMC, and with the CIEIAB and CIE94 the poorest for predicting the combined dataset of all color centers in the present study.