colour.temperature.uv_to_CCT_Ohno2013#

colour.temperature.uv_to_CCT_Ohno2013(uv: ArrayLike, cmfs: MultiSpectralDistributions | None = None, start: float | None = None, end: float | None = None, spacing: float | None = None) → NDArrayFloat[source]#

Return the correlated colour temperature \(T_{cp}\) and \(\Delta_{uv}\) from given CIE UCS colourspace uv chromaticity coordinates, colour matching functions and temperature range using Ohno (2013) method.

Parameters:

  • uv (ArrayLike) – CIE UCS colourspace uv chromaticity coordinates.

  • cmfs (MultiSpectralDistributions | None) – Standard observer colour matching functions, default to the CIE 1931 2 Degree Standard Observer.

  • start (float | None) – Temperature range start in kelvin degrees, default to 1000.

  • end (float | None) – Temperature range end in kelvin degrees, default to 100000.

  • spacing (float | None) – Spacing between values of the underlying planckian table expressed as a multiplier. Default to 1.001. The closer to 1.0, the higher the precision of the returned colour temperature \(T_{cp}\) and \(\Delta_{uv}\). 1.01 provides a good balance between performance and accuracy. spacing value must be greater than 1.

Returns:

Correlated colour temperature \(T_{cp}\), \(\Delta_{uv}\).

Return type:

numpy.ndarray

References

[Ohn14]

Examples

>>> from colour import MSDS_CMFS, SPECTRAL_SHAPE_DEFAULT
>>> cmfs = (
...     MSDS_CMFS["CIE 1931 2 Degree Standard Observer"]
...     .copy()
...     .align(SPECTRAL_SHAPE_DEFAULT)
... )
>>> uv = np.array([0.1978, 0.3122])
>>> uv_to_CCT_Ohno2013(uv, cmfs)  
array([  6.50747...e+03,   3.22334...e-03])