colour.models.Izazbz_to_XYZ

colour.models.Izazbz_to_XYZ(Izazbz, constants=None, method='Safdar 2017')[source]

Converts from \(I_za_zb_z\) colourspace to CIE XYZ tristimulus values.

Parameters
  • Izazbz (array_like) – \(I_za_zb_z\) colourspace array where \(I_z\) is the achromatic response, \(a_z\) is redness-greenness and \(b_z\) is yellowness-blueness.

  • constants (Structure, optional) – \(J_za_zb_z\) colourspace constants.

  • method (unicode, optional) – {‘Safdar 2017’, ‘Safdar 2021’, ‘ZCAM’}, Computation methods, Safdar 2021 and ZCAM are equivalent.

Returns

CIE XYZ tristimulus values under CIE Standard Illuminant D Series D65.

Return type

ndarray

Warning

The underlying SMPTE ST 2084:2014 transfer function is an absolute transfer function.

Notes

  • The underlying SMPTE ST 2084:2014 transfer function is an absolute transfer function, thus the domain and range values for the Reference and 1 scales are only indicative that the data is not affected by scale transformations.

Domain

Scale - Reference

Scale - 1

Izazbz

Iz : [0, 1]

az : [-1, 1]

bz : [-1, 1]

Iz : [0, 1]

az : [-1, 1]

bz : [-1, 1]

Range

Scale - Reference

Scale - 1

XYZ

UN

UN

References

[SCKL17], [SHRL21]

Examples

>>> Izazbz = np.array([0.01207793, 0.00924302, 0.00526007])
>>> Izazbz_to_XYZ(Izazbz)  
array([ 0.2065401...,  0.1219723...,  0.0513696...])