colour.hdr_CIELab_to_XYZ

colour.hdr_CIELab_to_XYZ(Lab_hdr, illuminant=array([ 0.3457, 0.3585]), Y_s=0.2, Y_abs=100, method=u'Fairchild 2011')[source]

Converts from hdr-CIELAB colourspace to CIE XYZ tristimulus values.

Parameters:
  • Lab_hdr (array_like) – hdr-CIELAB colourspace array.
  • illuminant (array_like, optional) – Reference illuminant xy chromaticity coordinates or CIE xyY colourspace array.
  • Y_s (numeric or array_like) – Relative luminance \(Y_s\) of the surround in domain [0, 1].
  • Y_abs (numeric or array_like) – Absolute luminance \(Y_{abs}\) of the scene diffuse white in \(cd/m^2\).
  • method (unicode, optional) – {‘Fairchild 2011’, ‘Fairchild 2010’}, Computation method.
Returns:

CIE XYZ tristimulus values.

Return type:

ndarray

Notes

  • Input illuminant xy chromaticity coordinates or CIE xyY colourspace array are in domain [0, \(\infty\)].
  • Output CIE XYZ tristimulus values are in range [0, math:infty].

References

Examples

>>> Lab_hdr = np.array([26.46461067, -24.613326, -4.84796811])
>>> hdr_CIELab_to_XYZ(Lab_hdr)  
array([ 0.0704953...,  0.1008    ,  0.0955831...])
>>> Lab_hdr = np.array([24.90206646, -46.83127607, -10.14274843])
>>> hdr_CIELab_to_XYZ(Lab_hdr, method='Fairchild 2010')
... 
array([ 0.0704953...,  0.1008    ,  0.0955831...])