INFLUENCE OF COLOR-MATCHING FUNCTIONS ON THRESHOLD AND LARGE COLOR DIFFERENCES

In the present work, we study the influence of colour-matching functio ns on the determination of colour-threshold differences (part I) and o f greater size (part II). For this, we have used the colour-matching f unctions of 16 different observers, the five CIE centres and 200 Munse ll samples. A previously operated and fully automated Wright colorimet er was used for the determination of colour-matching functions and col our-discrimination thresholds. The results for part I indicate that th e discrimination ellipses obtained with different colour-matching func tions (with some exceptions) had highly similar orientations, semiaxis relationships and areas, whereas the centres appeared to shift with r espect to each other, primarily in the blue area. The results for part II reveal important discrepancies between the different observers in evaluating any colour, and close agreement in evaluating colour differ ences. On the basis of the overall study, we deduce that the colour-ma tching functions of the observers have significant influence on the sp ecification of individual colours, but only slight effects on the dete rmination of small or large colour differences.