Digital signal processing tools are used to determine the proper sampling of color spectra and the effect of sampling on the accuracy of derived properties such as CIE tristimulus values and color rendering indexes. It is found that 10 nm sampling is adequate for most applications, but not for more exacting textile and paint matching applications. Special methods are proposed to treat the cases of color signals with delta function components such as fluorescent lights.

Fluorescent lamps are the most common lighting source for desktop publishing and standard viewing conditions. In order to predict the appearance of reflective material viewed under fluorescent lamps, the CIE tristimulus values must be computed. While these values are readily computed for most smoothly varying reflectances by using a simple summation, the presence of line spectra in the fluorescent lamps requires special treatment. This paper presents a method for the accurate computation of the tristimulus values. The effect of noise on the measurement is also considered.>