colour.colorimetry.intermediate_lightness_function_CIE1976#

colour.colorimetry.intermediate_lightness_function_CIE1976(Y: ArrayLike, Y_n: ArrayLike = 100) → NDArrayFloat[source]#

Compute the intermediate value \(f(Y/Y_n)\) from the specified luminance \(Y\) using the specified reference white luminance \(Y_n\) as per CIE 1976 recommendation.

Parameters:

  • Y (ArrayLike) – Luminance \(Y\).

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

Returns:

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

Return type:

numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

Y

100

100

Range

Scale - Reference

Scale - 1

f_Y_Y_n

1

1

References

[CIET14804h], [WS00l]

Examples

>>> intermediate_lightness_function_CIE1976(12.19722535)
...
np.float64(0.4959299...)
>>> intermediate_lightness_function_CIE1976(12.19722535, 95)
...
np.float64(0.5044821...)