colour.colorimetry.lightness_Fairchild2011¶

colour.colorimetry.lightness_Fairchild2011(Y: FloatingOrArrayLike, epsilon: FloatingOrArrayLike = 0.474, method: Union[Literal['hdr-CIELAB', 'hdr-IPT'], str] = 'hdr-CIELAB') → FloatingOrNDArray[source]¶

Compute Lightness \(L_{hdr}\) of given luminance \(Y\) using Fairchild and Chen (2011) method according to Michaelis-Menten kinetics.

Parameters

Y (FloatingOrArrayLike) – Luminance \(Y\).
epsilon (FloatingOrArrayLike) – \(\epsilon\) exponent.
method (Union[Literal['hdr-CIELAB', 'hdr-IPT'], str]) – Lightness \(L_{hdr}\) computation method.

Returns

Lightness \(L_{hdr}\).

Return type

numpy.floating or numpy.ndarray

Notes

Domain	Scale - Reference	Scale - 1
`Y`	[0, 1]	[0, 1]

Range	Scale - Reference	Scale - 1
`L_hdr`	[0, 100]	[0, 1]

References

[FC11]

Examples

>>> lightness_Fairchild2011(12.19722535 / 100)  
51.8529584...
>>> lightness_Fairchild2011(12.19722535 / 100, method='hdr-IPT')
... 
51.6431084...

colour.colorimetry.lightness_Fairchild2010

colour.colorimetry.lightness_Abebe2017