colour.XYZ_to_hdr_CIELab#

colour.XYZ_to_hdr_CIELab(XYZ: Domain1, illuminant: ArrayLike = CCS_ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65'], Y_s: Domain1 = 0.2, Y_abs: ArrayLike = 100, method: Literal['Fairchild 2011', 'Fairchild 2010'] | str = 'Fairchild 2011') → Range100[source]#

Convert from CIE XYZ tristimulus values to hdr-CIELAB colourspace.

Parameters:

XYZ (Domain1) – CIE XYZ tristimulus values.
illuminant (ArrayLike) – Reference illuminant CIE xy chromaticity coordinates or CIE xyY colourspace array.
Y_s (Domain1) – Relative luminance \(Y_s\) of the surround.
Y_abs (ArrayLike) – Absolute luminance \(Y_{abs}\) of the scene diffuse white in \(cd/m^2\).
method (Literal['Fairchild 2011', 'Fairchild 2010'] | str) – Computation method.

Returns:

hdr-CIELAB colourspace array.

Return type:

numpy.ndarray

Notes

Domain	Scale - Reference	Scale - 1
`XYZ`	1	1
`illuminant`	1	1
`Y_s`	1	1

Range	Scale - Reference	Scale - 1
`Lab_hdr`	100	1

Conversion to polar coordinates to compute the chroma \(C_{hdr}\) and hue \(h_{hdr}\) correlates can be safely performed with colour.Lab_to_LCHab() definition.
Conversion to cartesian coordinates from the Lightness \(L_{hdr}\), chroma \(C_{hdr}\) and hue \(h_{hdr}\) correlates can be safely performed with colour.LCHab_to_Lab() definition.

References

[FW10], [FC11]

Examples

>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
>>> XYZ_to_hdr_CIELab(XYZ)
array([ 51.8700206...,  60.4763385...,  32.1455191...])
>>> XYZ_to_hdr_CIELab(XYZ, method="Fairchild 2010")
array([  31.9962111...,  128.0076303...,   48.7695230...])

colour.XYZ_to_hdr_CIELab#

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