The CIE (International Commission on Illumination, French full name "Commission International L'Eclai rage") system is an international standard for color measurement established in 1931, which stipulates that red at 700nm, green at 546.1nm and blue at 435.8nm are the color light primary colors. The resulting 1.0X1.01931 CIE-XYZ system. Among them, X represents the red primary color, Y represents the green primary color, and Z represents the blue primary color. The triangle formed by X, Y, Z encompasses the entire spectral locus, making the chromaticity coordinates on and within the spectral locus positive (Fig. 8-10).
1964CIE Supplementary Colorimetric System. If the color to be observed or measured is a large area, and the field of view angle is greater than 4 degrees, because the rod cells outside the macula of the retina participate in the stimulation, the color vision will change to a certain extent, which will reduce the saturation of the observed color , the color field of view appears uneven. Therefore, it is a colorimetric measurement system suitable for a large field of view of 10 degrees. In 1976, it was revised to CIEL* Kuang b*. This system uses three parameters, one is brightness L (lumi nance), and the other two are color components, respectively a, representing from green (green) to red (red); the other is b, representing from blue ( bl ue) to yellow (yellow).
