colour.XYZ_to_Hunter_Lab

colour.XYZ_to_Hunter_Lab(XYZ, XYZ_n=array([ 96.38, 100., 82.45]), K_ab=array([ 173.51, 58.48]))[source]

Converts from CIE XYZ tristimulus values to Hunter L,a,b colour scale.

Parameters:
  • XYZ (array_like) – CIE XYZ tristimulus values.
  • XYZ_n (array_like, optional) – Reference illuminant tristimulus values.
  • K_ab (array_like, optional) – Reference illuminant chromaticity coefficients, if K_ab is set to None it will be computed using colour.XYZ_to_K_ab_HunterLab1966().
Returns:

Hunter L,a,b colour scale array.

Return type:

ndarray

Notes

  • Input CIE XYZ and reference illuminant tristimulus values are in domain [0, 100].
  • Output Lightness \(L^*\) is in range [0, 100].

References

Examples

>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313]) * 100
>>> D50 = HUNTERLAB_ILLUMINANTS[
...     'CIE 1931 2 Degree Standard Observer']['D50']
>>> XYZ_to_Hunter_Lab(XYZ, D50.XYZ_n, D50.K_ab)   
array([ 31.7490157..., -15.1146262...,  -2.7866075...])