XYZ tristimulus values

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

By creating scales for hue, lightness, and chroma, we can now measure color numerically. Other methods for expressing color numerically were developed by the Commission Internationale de l Eclairage (CIE), an international organization concerned with light and color. The two most widely known of these methods are the Yxy color space, devised based on tristimulus values XYZ defined by CIE, and... 

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 ... 

Chromaticity diagram A 2D plot of the chromaticity values X and y derived from the tristimulus values XYZ. A plot of CIE color space. 

Tristimulus values Three values (XYZ) calculated using a spectrum in the visible range, standard illumirrate values, and weighting factors associated with the CIE color space system. 

An instrument for psychophysical analysis— provides measurements that correlate with human eye-brain perception. Coiorimetric data directly read and provided as tristimulus values (XYZ, L, a, b, etc.). 

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 ... 

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. 

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. 

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