colour.sd_to_aces_relative_exposure_values¶
-
colour.
sd_to_aces_relative_exposure_values
(sd, illuminant=SpectralDistribution(name='D65', ...), apply_chromatic_adaptation=False, chromatic_adaptation_transform='CAT02')[source]¶ Converts given spectral distribution to ACES2065-1 colourspace relative exposure values.
- Parameters
sd (SpectralDistribution) – Spectral distribution.
illuminant (SpectralDistribution, optional) – Illuminant spectral distribution.
apply_chromatic_adaptation (bool, optional) – Whether to apply chromatic adaptation using given transform.
chromatic_adaptation_transform (unicode, optional) – {‘CAT02’, ‘XYZ Scaling’, ‘Von Kries’, ‘Bradford’, ‘Sharp’, ‘Fairchild’, ‘CMCCAT97’, ‘CMCCAT2000’, ‘CAT02_BRILL_CAT’, ‘Bianco’, ‘Bianco PC’}, Chromatic adaptation transform.
- Returns
ACES2065-1 colourspace relative exposure values array.
- Return type
ndarray, (3,)
Notes
Range
Scale - Reference
Scale - 1
XYZ
[0, 100]
[0, 1]
The chromatic adaptation method implemented here is a bit unusual as it involves building a new colourspace based on ACES2065-1 colourspace primaries but using the whitepoint of the illuminant that the spectral distribution was measured under.
References
[For18], [TheAoMPAaSciencesScienceaTCouncilAcademyCESACESPSubcommittee14c], [TheAoMPAaSciencesScienceaTCouncilAcademyCESACESPSubcommittee14d], [TheAoMPAaSciencesScienceaTCouncilAcademyCESACESPSubcommittee]
Examples
>>> from colour import COLOURCHECKERS_SDS >>> sd = COLOURCHECKERS_SDS['ColorChecker N Ohta']['dark skin'] >>> sd_to_aces_relative_exposure_values(sd) array([ 0.1171785..., 0.0866347..., 0.0589707...]) >>> sd_to_aces_relative_exposure_values(sd, ... apply_chromatic_adaptation=True) array([ 0.1180766..., 0.0869023..., 0.0589104...])