colour.colorimetry.lightness_Fairchild2011

colour.colorimetry.lightness_Fairchild2011(Y, epsilon=0.474, method='hdr-CIELAB')[source]

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

Parameters
  • Y (array_like) – luminance \(Y\).

  • epsilon (numeric or array_like, optional) – \(\epsilon\) exponent.

  • method (unicode, optional) – {‘hdr-CIELAB’, ‘hdr-IPT’}, Lightness \(L_{hdr}\) computation method.

Returns

Lightness \(L_{hdr}\).

Return type

array_like

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...