XYZ tristimulus values

Therefore, the tristimulus values XYZ can be expressed as Eqs. 21-23 using the absorption spectra data [12]  

Subsequent to determining standard and lot tristimulus XYZ values, one simply plugs those calculated values into the CIE Lab color equations. Why the CIE system Because CMC uses the DLab values, generated in CIE color space, to determine DC, DH, and eventually CMC DE. 

If your old batch color control system is in Hunter and you want to convert to CMC, the first step is to transform all old DLab values back into tristimulus XYZ values. 

QxQy coordinates are complementary xy chromaticity coordinates as shown in Fig. 3. These are analogues of the xy coordinates which are calculated from tristimulus XYZ values in order to plot color points in a two-dimensional diagram [11]. In this case, QxQy values are calculated by the same procedure adopted in the case of xy coordinates, but the transmission spectra T(X) are replaced with the absorption spectra A(X). The equations for QxQy are given as follows  

Color The color of the film can affect the consumer acceptance of coated produce (60). Five different color systems XYZ, Yxy, L a b, L C H° and Hunter Lab are used to express absolute chromaticity. Color system XYZ is measured as tristimulus values of color and forms the basis for most calculations. In the color system Yxy, Y is a lightness factor expressed as a percentage based on a perfect reflection of 100%. x and y are chromaticity coordinates defined by the following equations  

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