
The CIE system
of colorimetry
21
For an approachable, nonmathe-
matical introduction to color
physics and perception, see
Rossotti, Hazel,
Co/our: Why the
World Isn't Grey
(Princeton, N.J.:
Princeton Univ. Press, 1983).
The
Commission lnternationale de L'E-clairage (CIE) has
defined a system that maps a
spectral power distribu-
tion
(SPD) of physics into a triple of numerical values-
CiE
XYZ tristimuius values - that form the math-
ematical coordinates of color space. In this chapter,
I describe the CIE system. In the following chapter,
Color science for video, I will explain how these XYZ tris-
timulus