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colour.quality Package

Module Contents

class colour.quality.CRI_Specification

Bases: colour.quality.cri.CRI_Specification

Defines the colour rendering index colour quality specification.

Parameters:
  • Q_a (numeric) – Colour rendering index Qa.
  • Q_as (dict) – Individual colour rendering indexes data for each sample.
  • colorimetry_data (tuple) – Colorimetry data for the test and reference computations.
colour.quality.colour_rendering_index(spd_test, additional_data=False)

Returns the colour rendering index Qa of given spectral power distribution.

Parameters:
  • spd_test (SpectralPowerDistribution) – Test spectral power distribution.
  • additional_data (bool, optional) – Output additional data.
Returns:

Colour rendering index.

Return type:

numeric or CRI_Specification

Examples

>>> from colour import ILLUMINANTS_RELATIVE_SPDS
>>> spd = ILLUMINANTS_RELATIVE_SPDS.get('F2')
>>> colour_rendering_index(spd)  
64.1507331...
class colour.quality.CQS_Specification

Bases: colour.quality.cqs.CQS_Specification

Defines the CQS colour quality specification.

Parameters:
  • Q_a (numeric) – Colour quality scale Qa.
  • Q_f (numeric) – Colour fidelity scale Qf intended to evaluate the fidelity of object colour appearances (compared to the reference illuminant of the same correlated colour temperature and illuminance).
  • Q_p (numeric) – Colour preference scale Qp similar to colour quality scale Qa but placing additional weight on preference of object colour appearance. This metric is based on the notion that increases in chroma are generally preferred and should be rewarded.
  • Q_g (numeric) – Gamut area scale Qg representing the relative gamut formed by the (a, b) coordinates of the 15 samples illuminated by the test light source in the CIE LAB object colourspace.
  • Q_d (numeric) – Relative gamut area scale Qd.
  • Q_as (dict) – Individual CQS data for each sample.
  • colorimetry_data (tuple) – Colorimetry data for the test and reference computations.
colour.quality.colour_quality_scale(spd_test, additional_data=False)

Returns the colour quality scale of given spectral power distribution.

Parameters:
  • spd_test (SpectralPowerDistribution) – Test spectral power distribution.
  • additional_data (bool, optional) – Output additional data.
Returns:

Color quality scale.

Return type:

numeric or CQS_Specification

Examples

>>> from colour import ILLUMINANTS_RELATIVE_SPDS
>>> spd = ILLUMINANTS_RELATIVE_SPDS.get('F2')
>>> colour_quality_scale(spd)  
64.6860580...