colour.quality Package¶

Sub-Packages¶

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 \(Q_a\). 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 \(Q_a\) 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:

Parameters:	Q_a (numeric) – Colour quality scale \(Q_a\). Q_f (numeric) – Colour fidelity scale \(Q_f\) 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 \(Q_p\) similar to colour quality scale \(Q_a\) 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 \(Q_g\) 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 \(Q_d\). Q_as (dict) – Individual CQS data for each sample. colorimetry_data (tuple) – Colorimetry data for the test and reference computations.

Q_a (numeric) – Colour quality scale \(Q_a\).
Q_f (numeric) – Colour fidelity scale \(Q_f\) 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 \(Q_p\) similar to colour quality scale \(Q_a\) 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 \(Q_g\) 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 \(Q_d\).
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...