等明度・高彩度色票の測色上の色差と知覚される色差との対応

Abstract

Perceived colour-differences of colour chips are estimated subjectively by means of ratio estimation method under standard illuminant A and daylight D65, and are compared with their colorimetric ones in the CIE 1976 L*u*v*, the CIE 1976 L*u*v*, a modified L*u*v*, and a modified Cube-root colour spaces.The set of colour chips used in the experiment consists of one hundred and sixty hues with constant value and chroma of 6/8 in the Munsell renotation system. Colorimetric colour-differences of the pairs of colour chips are within the range of 0.89 to 17.56 under daylight illuminant D65 in the CIE 1976 L*a*b* uniform colour space.Results obtained are summarized as follows:(1) Relative values of perceived colour-differences change little even when the illuminant changes from D65 to A, and the constancy of perceived colour-difference holds as well as in the case of colour chips of lower chroma.(2) Under the daylight D65, the degrees of correlation between perceived colour-differences and colorimetric ones are little different among the colour spaces examined, but under the illminant A the degree in the CIE L*u*v* colour space is a little lower than the others.(3) The variation with hue angle of the ratio of colorimetric colour-differences under the illuminant A and those under the illuminant D65 in the CIE L*u*v* colour space is the largest, and that in the cube-root colour space is the smallest.(4) The correction to the chromatic adaptation in terms of colour-differences is well done in the cube-root colour space, and it is scarcely done in the CIE L*uv* colour space.