colour.XYZ_to_hdr_CIELab¶
-
colour.
XYZ_to_hdr_CIELab
(XYZ, illuminant=array([ 0.3127, 0.329 ]), Y_s=0.2, Y_abs=100, method='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.
- 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
Domain Scale - Reference Scale - 1 XYZ
[0, 1] [0, 1] illuminant
[0, 1] [0, 1] Y_s
[0, 1] [0, 1] Range Scale - Reference Scale - 1 Lab_hdr
L_hdr
: [0, 100]a_hdr
: [-100, 100]b_hdr
: [-100, 100]L_hdr
: [0, 1]a_hdr
: [-1, 1]b_hdr
: [-1, 1]- 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.
References
Examples
>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952]) >>> XYZ_to_hdr_CIELab(XYZ) # doctest: +ELLIPSIS array([ 51.8700206..., 60.4763385..., 32.1455191...]) >>> XYZ_to_hdr_CIELab(XYZ, method='Fairchild 2010') # doctest: +ELLIPSIS array([ 31.9962111..., 128.0076303..., 48.7695230...])