colour.lightness

colour.lightness(Y: Domain100, method: Literal['Abebe 2017', 'CIE 1976', 'Glasser 1958', 'Fairchild 2010', 'Fairchild 2011', 'Wyszecki 1963'] | str = 'CIE 1976', **kwargs: Any) → Range100

Compute the lightness \(L\) from the specified luminance \(Y\).

Parameters:

• Y (Domain100) – Luminance \(Y\).

• method (Literal['Abebe 2017', 'CIE 1976', 'Glasser 1958', 'Fairchild 2010', 'Fairchild 2011', 'Wyszecki 1963'] | str) – Computation method.

• Y_n – {colour.colorimetry.lightness_Abebe2017(), colour.colorimetry.lightness_CIE1976()}, White reference luminance \(Y_n\).

• epsilon – {colour.colorimetry.lightness_Fairchild2010(), colour.colorimetry.lightness_Fairchild2011()}, \(\epsilon\) exponent.

• kwargs (Any)

Returns:

Lightness \(L\).

Return type:

numpy.ndarray

Notes

Domain	Scale - Reference	Scale - 1
Y	100	1

Range	Scale - Reference	Scale - 1
L	100	1

References

[APLR17], [CIET14804h], [FW10], [FC11], [GMRS58], [Wikipedia07a], [Wys63], [WS00l]

Examples

>>> lightness(12.19722535)
np.float64(41.5278758...)
>>> lightness(12.19722535, Y_n=100)
np.float64(41.5278758...)
>>> lightness(12.19722535, Y_n=95)
np.float64(42.5199307...)
>>> lightness(12.19722535, method="Glasser 1958")
np.float64(39.8351264...)
>>> lightness(12.19722535, method="Wyszecki 1963")
np.float64(40.5475745...)
>>> lightness(12.19722535, epsilon=0.710, method="Fairchild 2011")
...
np.float64(29.8295108...)
>>> lightness(12.19722535, epsilon=0.710, method="Fairchild 2011")
...
np.float64(29.8295108...)
>>> lightness(12.19722535, method="Abebe 2017")
...
np.float64(48.6955571...)