colour.XYZ_to_Nayatani95¶

colour.XYZ_to_Nayatani95(XYZ, XYZ_n, Y_o, E_o, E_or, n=1)[source]¶

Computes the Nayatani (1995) colour appearance model correlates.

Parameters:	XYZ (array_like) – CIE XYZ tristimulus values of test sample / stimulus in domain [0, 100]. XYZ_n (array_like) – CIE XYZ tristimulus values of reference white in domain [0, 100]. Y_o (numeric or array_like) – Luminance factor \(Y_o\) of achromatic background as percentage in domain [0.18, 1.0] E_o (numeric or array_like) – Illuminance \(E_o\) of the viewing field in lux. E_or (numeric or array_like) – Normalising illuminance \(E_{or}\) in lux usually in domain [1000, 3000] n (numeric or array_like, optional) – Noise term used in the non linear chromatic adaptation model.
Returns:	Nayatani (1995) colour appearance model specification.
Return type:	Nayatani95_Specification

Warning

The input domain of that definition is non standard!

Notes

Input CIE XYZ tristimulus values are in domain [0, 100].
Input CIE XYZ_n tristimulus values are in domain [0, 100].

References

Examples

>>> XYZ = np.array([19.01, 20.00, 21.78])
>>> XYZ_n = np.array([95.05, 100.00, 108.88])
>>> Y_o = 20.0
>>> E_o = 5000.0
>>> E_or = 1000.0
>>> XYZ_to_Nayatani95(XYZ, XYZ_n, Y_o, E_o, E_or)  
Nayatani95_Specification(Lstar_P=49.9998829..., C=0.0133550..., h=257.5232268..., s=0.0133550..., Q=62.6266734..., M=0.0167262..., H=None, HC=None, Lstar_N=50.0039154...)