colour.temperature.xy_to_CCT_CIE_D#

colour.temperature.xy_to_CCT_CIE_D(xy: ArrayLike, optimisation_kwargs: Dict | None = None) → FloatingOrNDArray[source]#

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

Parameters:

xy (ArrayLike) – CIE xy chromaticity coordinates.
optimisation_kwargs (Dict | None) – Parameters for scipy.optimize.minimize() definition.

Returns:

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

Return type:

numpy.floating or numpy.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

[WS00k]

Examples

>>> xy_to_CCT_CIE_D(np.array([0.31270775, 0.32911283]))
... 
6504.3895840...