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.

  • XYZ_n (array_like) – CIE XYZ tristimulus values of reference white.

  • Y_o (numeric or array_like) – Luminance factor \(Y_o\) of achromatic background as percentage normalised to domain [0.18, 1.0] in ‘Reference’ domain-range scale.

  • 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 normalised to 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

Notes

Domain

Scale - Reference

Scale - 1

XYZ

[0, 100]

[0, 1]

XYZ_n

[0, 100]

[0, 1]

Range

Scale - Reference

Scale - 1

Nayatani95_Specification.h

[0, 360]

[0, 1]

References

[Fai13g], [NSY95]

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(L_star_P=49.9998829..., C=0.0133550..., h=257.5232268..., s=0.0133550..., Q=62.6266734..., M=0.0167262..., H=None, HC=None, L_star_N=50.0039154...)