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...