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 CIE 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) array([ 51.8700206..., 60.4763385..., 32.1455191...]) >>> XYZ_to_hdr_CIELab(XYZ, method='Fairchild 2010') array([ 31.9962111..., 128.0076303..., 48.7695230...])