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cieXYZ2xyz

The cieXYZ2xyz function calculates the normalized CIE 1931 chromaticity coordinates from standard CIE X,Y,Z tristimulus values. Any errors in the data set or in results generated with the Lighting Toolbox are not in the liability of the CIE nor me, see licence.

Usage:

[xyz,x,y,z] = cieXYZ2xyz(XYZ)

Where:

ParameterDescription
xyzAre the returned normalized tristimulus values in CIE 1931 colour space.
XYZAre the standard tristimulus values in CIE 1931 colour space.

Example:

Normalized tristimulus values:

XYZ = [685.9847 721.7317 785.84229];
xyz = cieXYZ2xyz(XYZ)

Result:

xyz =

   0.3127   0.3290   0.3582

Determine the whitepoint of CIE standard illuminant A using cone-fundamental tristimulus values for 2° standard observer:

lam = 380:780;
spec = ciespec(lam,'A');
XYZ = ciespec2unit(lam,spec,'xyz');
xyz = cieXYZ2xyz(XYZ)
plotciexy(xyz(1),xyz(2))

See also: ciespec, ciespec2unit, plotciexy, ciewhitepoint

Result:

xyz =

   0.4475   0.4075   0.1450

Reference

ISO/CIE 12664-3:2019(E): Colorimetry - Part 3: CIE tristimulus values. Commission International de l’Éclairage (CIE), Vienna Austria, 2019.

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