colour.lightness

colour.lightness(Y, method='CIE 1976', **kwargs)[source]

Returns the Lightness \(L\) of given luminance \(Y\) using given method.

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

  • method (unicode, optional) – {‘CIE 1976’, ‘Glasser 1958’, ‘Wyszecki 1963’, ‘Fairchild 2010’, ‘Fairchild 2011’}, Computation method.

Other Parameters
Returns

Lightness \(L\).

Return type

numeric or array_like

Notes

Domain

Scale - Reference

Scale - 1

Y

[0, 100]

[0, 1]

Range

Scale - Reference

Scale - 1

L

[0, 100]

[0, 1]

References

[CIET14804f], [FW10], [FC11], [GMRS58], [Wikipedia07d], [Wys63], [WS00c]

Examples

>>> lightness(12.19722535)  
41.5278758...
>>> lightness(12.19722535, Y_n=100)  
41.5278758...
>>> lightness(12.19722535, Y_n=95)  
42.5199307...
>>> lightness(12.19722535, method='Glasser 1958')  
39.8351264...
>>> lightness(12.19722535, method='Wyszecki 1963')  
40.5475745...
>>> lightness(12.19722535, epsilon=0.710, method='Fairchild 2011')
... 
29.8295108...