colour.colorimetry.luminance_Fairchild2011

colour.colorimetry.luminance_Fairchild2011(L_hdr, epsilon=0.71, method=u'hdr-CIELAB')[source]

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

Parameters:
  • L_hdr (array_like) – Lightness \(L_{hdr}\).
  • epsilon (numeric or array_like, optional) – \(\epsilon\) exponent.
  • method (unicode, optional) – {‘hdr-CIELAB’, ‘hdr-IPT’}, Lightness \(L_{hdr}\) computation method.
Returns:

luminance \(Y\).

Return type:

array_like

Warning

The output range of that definition is non standard!

Notes

  • Output luminance \(Y\) is in range [0, math:infty].

References

Examples

>>> luminance_Fairchild2011(26.459509817572265)  
0.1007999...
>>> luminance_Fairchild2011(26.352467267703549, method='hdr-IPT')
... 
0.1007999...