colour.spectral_to_XYZ

colour.spectral_to_XYZ(spd, cmfs=XYZ_ColourMatchingFunctions(name='CIE 1931 2 Degree Standard Observer', ...), illuminant=SpectralPowerDistribution(name='1 Constant', ...), method=u'ASTM E308-15', **kwargs)

Converts given spectral power distribution to CIE XYZ tristimulus values using given colour matching functions, illuminant and method.

Parameters:

• spd (SpectralPowerDistribution) – Spectral power distribution.
• cmfs (XYZ_ColourMatchingFunctions) – Standard observer colour matching functions.
• illuminant (SpectralPowerDistribution, optional) – Illuminant spectral power distribution.
• method (unicode, optional) – {‘ASTM E308-15’, ‘Integration’}, Computation method.

Other Parameters:  

• use_practice_range (bool, optional) – {colour.colorimetry.spectral_to_XYZ_ASTME30815()}, Practise ASTM E308-15 working wavelengths range is [360, 780], if True this argument will trim the colour matching functions appropriately.
• mi_5nm_omission_method (bool, optional) – {colour.colorimetry.spectral_to_XYZ_ASTME30815()}, 5 nm measurement intervals spectral power distribution conversion to tristimulus values will use a 5 nm version of the colour matching functions instead of a table of tristimulus weighting factors.
• mi_20nm_interpolation_method (bool, optional) – {colour.colorimetry.spectral_to_XYZ_ASTME30815()}, 20 nm measurement intervals spectral power distribution conversion to tristimulus values will use a dedicated interpolation method instead of a table of tristimulus weighting factors.

Returns:

CIE XYZ tristimulus values.

Return type:

ndarray, (3,)

Warning

The output range of that definition is non standard!

Notes

• Output CIE XYZ tristimulus values are in range [0, 100].

References

• [ASTMInternational11]
• [ASTMInternational15]
• [WS00d]

Examples

>>> from colour import (
...     CMFS, ILLUMINANTS_RELATIVE_SPDS, SpectralPowerDistribution)
>>> cmfs = CMFS['CIE 1931 2 Degree Standard Observer']
>>> data = {
...     400: 0.0641,
...     420: 0.0645,
...     440: 0.0562,
...     460: 0.0537,
...     480: 0.0559,
...     500: 0.0651,
...     520: 0.0705,
...     540: 0.0772,
...     560: 0.0870,
...     580: 0.1128,
...     600: 0.1360,
...     620: 0.1511,
...     640: 0.1688,
...     660: 0.1996,
...     680: 0.2397,
...     700: 0.2852
... }
>>> spd = SpectralPowerDistribution(data)
>>> illuminant = ILLUMINANTS_RELATIVE_SPDS['D50']
>>> spectral_to_XYZ(spd, cmfs, illuminant)
... 
array([ 11.5290265...,   9.9502091...,   4.7098882...])
>>> spectral_to_XYZ(spd, cmfs, illuminant, use_practice_range=False)
... 
array([ 11.5291275...,   9.9502369...,   4.7098811...])
>>> spectral_to_XYZ(spd, cmfs, illuminant, method='Integration')
... 
array([ 11.5296285...,   9.9499467...,   4.7066079...])