colour.luminance

colour.luminance(LV, method=u'CIE 1976', **kwargs)

Returns the luminance \(Y\) of given Lightness \(L^*\) or given Munsell value \(V\).

Parameters:

• LV (numeric or array_like) – Lightness \(L^*\) or Munsell value \(V\).
• method (unicode, optional) – {‘CIE 1976’, ‘Newhall 1943’, ‘ASTM D1535-08’, ‘Fairchild 2010’, ‘Fairchild 2011’}, Computation method.

Other Parameters:  

• Y_n (numeric or array_like, optional) – {colour.colorimetry.luminance_CIE1976()}, White reference luminance \(Y_n\).
• epsilon (numeric or array_like, optional) – {colour.colorimetry.lightness_Fairchild2010(), colour.colorimetry.lightness_Fairchild2011()}, \(\epsilon\) exponent.

Returns:

luminance \(Y\).

Return type:

numeric or array_like

Notes

• Input LV is in domain [0, 100], [0, 10] or [0, 1] and optional luminance \(Y_n\) is in domain [0, 100].
• Output luminance \(Y\) is in range [0, 100] or [0, math:infty].

References

• [ASTMInternational08]
• [FW10]
• [FC11]
• [Lin03a]
• [NNJ43]
• [Wikp]
• [WS00a]

Examples

>>> luminance(37.98562910)  
10.0800000...
>>> luminance(37.98562910, Y_n=100)  
10.0800000...
>>> luminance(37.98562910, Y_n=95)  
9.5760000...
>>> luminance(3.74629715, method='Newhall 1943')  
10.4089874...
>>> luminance(3.74629715, method='ASTM D1535-08')  
10.1488096...
>>> luminance(24.902290269546651, epsilon=1.836, method='Fairchild 2010')
... 
0.1007999...