The study on effective factors in choosing weight function of spectrophotometric color matching

In the color science, the spectrophotometric matching tries to minimize the spectral differences between the target and the matched within visible range of spectrum. While this strategy does not usually lead to acceptable color differences, more balanced color differences under different set of viewing condition is expected. The colorimetric performance of this type of matching could be improved by implementation of weighted least square technique where the spectral differences become minimum in some particular wavelengths. Usually, the colour matching functions are used as weighting function. In this paper, a new weighting function composed of linear combination of two standard light sources, i.e. D65 and A illuminants, and the spectral sensitivity of standard observer is used as weighting tools. The employed method improves the mean of color difference values under the employed illuminants and viewing condition. While in depth study is still needed, the primary results show that the spectral patterns of target also play an important effect in selection of suitable weight.