colour.colorimetry.intermediate_lightness_function_CIE1976#

colour.colorimetry.intermediate_lightness_function_CIE1976(Y: FloatingOrArrayLike, Y_n: FloatingOrArrayLike = 100) FloatingOrNDArray[source]#

Return the intermediate value \(f(Y/Yn)\) in the Lightness \(L^*\) computation for given luminance \(Y\) using given reference white luminance \(Y_n\) as per CIE 1976 recommendation.

Parameters
  • Y (FloatingOrArrayLike) – Luminance \(Y\).

  • Y_n (FloatingOrArrayLike) – White reference luminance \(Y_n\).

Returns

Intermediate value \(f(Y/Yn)\).

Return type

numpy.floating or numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

Y

[0, 100]

[0, 100]

Range

Scale - Reference

Scale - 1

f_Y_Y_n

[0, 1]

[0, 1]

References

[CIET14804h], [WS00l]

Examples

>>> intermediate_lightness_function_CIE1976(12.19722535)
... 
0.4959299...
>>> intermediate_lightness_function_CIE1976(12.19722535, 95)
... 
0.5044821...