colour.colorimetry.lightness_Abebe2017#

colour.colorimetry.lightness_Abebe2017(Y: FloatingOrArrayLike, Y_n: FloatingOrArrayLike = 100, method: Union[Literal['Michaelis-Menten', 'Stevens'], str] = 'Michaelis-Menten') FloatingOrNDArray[source]#

Compute Lightness \(L\) of given luminance \(Y\) using Abebe, Pouli, Larabi and Reinhard (2017) method according to Michaelis-Menten kinetics or Stevens’s Power Law.

Parameters:
  • Y (FloatingOrArrayLike) – Luminance \(Y\) in \(cd/m^2\).

  • Y_n (FloatingOrArrayLike) – Adapting luminance \(Y_n\) in \(cd/m^2\).

  • method (Union[Literal['Michaelis-Menten', 'Stevens'], str]) – Lightness \(L\) computation method.

Returns:

Lightness \(L\).

Return type:

numpy.floating or numpy.ndarray

Notes

  • Abebe, Pouli, Larabi and Reinhard (2017) method uses absolute luminance levels, thus the domain and range values for the Reference and 1 scales are only indicative that the data is not affected by scale transformations.

Domain

Scale - Reference

Scale - 1

Y

UN

UN

Y_n

UN

UN

Range

Scale - Reference

Scale - 1

L

UN

UN

References

[]

Examples

>>> lightness_Abebe2017(12.19722535)  
0.4869555...
>>> lightness_Abebe2017(12.19722535, method='Stevens')
... 
0.4745447...