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

[CIETC1-482004m], [Fairchild2010], [Fairchild2011], [Glasser1958a], [Wikipedia2007c], [Wyszecki1963b], [Wyszecki2000bd]

Examples

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