Background
The International Commission on Illumination
(CIE) recommended CIE color specification system
as the basis for colorimetry [1]. The ISO and CIE are
also provided a series of joint standards [2–4]. The
fundamental of colorimetry is Tristimulus Values
[4]. They are used for color communication and
reproduction. The three key elements of color perception are: human vision system, light, and object.
If missing one of three elements, we will not be able
to perceive color.