colour.temperature.xy_to_CCT_CIE_D

colour.temperature.xy_to_CCT_CIE_D(xy, optimisation_parameters=None)[source]

Returns the correlated colour temperature \(T_{cp}\) of a CIE Illuminant D Series from its CIE xy chromaticity coordinates.

Parameters:
  • xy (array_like) – CIE xy chromaticity coordinates.
  • optimisation_parameters (dict_like, optional) – Parameters for scipy.optimize.minimize() definition.
Returns:

Correlated colour temperature \(T_{cp}\).

Return type:

ndarray

Warning

The CIE Illuminant D Series method does not give an analytical inverse transformation to compute the correlated colour temperature \(T_{cp}\) from given CIE xy chromaticity coordinates, the current implementation relies on optimization using scipy.optimize.minimize() definition and thus has reduced precision and poor performance.

References

[Wyszecki2000z]

Examples

>>> xy_to_CCT_CIE_D(np.array([0.31270775, 0.32911283]))
... # doctest: +ELLIPSIS
6504.3895840...