colour.XYZ_to_hdr_CIELab¶
-
colour.
XYZ_to_hdr_CIELab
(XYZ, illuminant=array([ 0.3457, 0.3585]), Y_s=0.2, Y_abs=100, method=u'Fairchild 2011')[source]¶ Converts from CIE XYZ tristimulus values to hdr-CIELAB colourspace.
Parameters: - XYZ (array_like) – CIE XYZ tristimulus values.
- 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: hdr-CIELAB colourspace array.
Return type: ndarray
Notes
- Conversion to polar coordinates to compute the chroma \(C_{hdr}\)
and hue \(h_{hdr}\) correlates can be safely performed with
colour.Lab_to_LCHab()
definition. - Conversion to cartesian coordinates from the Lightness
\(L_{hdr}\), chroma \(C_{hdr}\) and hue \(h_{hdr}\)
correlates can be safely performed with
colour.LCHab_to_Lab()
definition. - Input CIE XYZ tristimulus values are in domain [0, math:infty].
- Input illuminant xy chromaticity coordinates or CIE xyY colourspace array are in domain [0, \(\infty\)].
References
Examples
>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313]) >>> XYZ_to_hdr_CIELab(XYZ) array([ 26.4646106..., -24.613326 ..., -4.8479681...]) >>> XYZ_to_hdr_CIELab(XYZ, method='Fairchild 2010') array([ 24.9020664..., -46.8312760..., -10.1427484...])