colour.appearance.coefficient_K_Br_Nayatani1997#

colour.appearance.coefficient_K_Br_Nayatani1997(L_a: float | DTypeFloat) → DTypeFloat[source]#
colour.appearance.coefficient_K_Br_Nayatani1997(L_a: NDArray) → NDArrayFloat
colour.appearance.coefficient_K_Br_Nayatani1997(L_a: ArrayLike) → DTypeFloat | NDArrayFloat

Compute the \(K_{Br}\) coefficient for Nayatani (1997) HKE computations.

Parameters:

L_a – Adapting luminance in \(cd/m^2\).

Returns:

\(K_{Br}\) coefficient for Nayatani (1997) HKE methods.

Return type:

numpy.ndarray

Notes

  • The \(K_{Br}\) coefficient is normalised to unity around \(63.66cd/m^2\).

References

[Nay97]

Examples

>>> L_a_values = [10 + i * 20 for i in range(5)]
>>> coefficient_K_Br_Nayatani1997(L_a_values)  
array([ 0.7134481...,  0.8781172...,  0.9606248...,  1.0156689...,  1.0567008...])
>>> coefficient_K_Br_Nayatani1997(63.66)  
1.0001284...