METHODS FOR QUANTIFYING METAMERISM .2. INSTRUMENTAL METHODS

This is the second part of this series of articles, in which the exper imental data described in Part 1 are used to evaluate three types of m etamerism indices. The results show that the index based upon one of t he three advanced colour-difference formulae (CMC, BFD, and CIE94) gav e a quite satisfactory prediction to the visual results. The degree of precision from these formulae is equal to or higher than the typical observer precision found in this study. A set of colour-matching funct ions was also derived. In comparison with those of the CIE 1964 standa rd colorimetric observer, the new set gives closer agreement with the visual results, particularly under source D-65. This new set could be used for indicating the degree of observer metamerism. Another set of experimental data was also assessed. Similar tests were conducted and the results confirm the earlier findings. The advanced colour-differen ce formulae can be confidently used for evaluating the degree of metam erism for industrial applications.