colour.temperature.uv_to_CCT_Ohno2013¶

colour.temperature.uv_to_CCT_Ohno2013(uv, cmfs=XYZ_ColourMatchingFunctions(name='CIE 1931 2 Degree Standard Observer', ...), start=1000, end=100000, count=10, iterations=6)[source]¶

Returns 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.

The iterations parameter defines the calculations precision: The higher its value, the more planckian tables will be generated through cascade expansion in order to converge to the exact solution.

Parameters

uv (array_like) – CIE UCS colourspace uv chromaticity coordinates.
cmfs (XYZ_ColourMatchingFunctions, optional) – Standard observer colour matching functions.
start (numeric, optional) – Temperature range start in kelvins.
end (numeric, optional) – Temperature range end in kelvins.
count (int, optional) – Temperatures count in the planckian tables.
iterations (int, optional) – Number of planckian tables to generate.

Returns

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

Return type

ndarray

References

[Ohn14]

Examples

>>> from colour import DEFAULT_SPECTRAL_SHAPE, STANDARD_OBSERVER_CMFS
>>> cmfs = (
...     STANDARD_OBSERVER_CMFS['CIE 1931 2 Degree Standard Observer'].
...     copy().align(DEFAULT_SPECTRAL_SHAPE)
... )
>>> uv = np.array([0.1978, 0.3122])
>>> # Doctests skipping for Python 2.x compatibility.
>>> uv_to_CCT_Ohno2013(uv, cmfs)  
array([  6.5074738...e+03,   3.2233460...e-03])