colour.hdr_CIELab_to_XYZ

colour.hdr_CIELab_to_XYZ(Lab_hdr, illuminant=array([0.3127, 0.329]), Y_s=0.2, Y_abs=100, method='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 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

CIE XYZ tristimulus values.

Return type

ndarray

Notes

Domain

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]

illuminant

[0, 1]

[0, 1]

Y_s

[0, 1]

[0, 1]

Range

Scale - Reference

Scale - 1

XYZ

[0, 1]

[0, 1]

References

[FW10], [FC11]

Examples

>>> Lab_hdr = np.array([51.87002062, 60.4763385, 32.14551912])
>>> hdr_CIELab_to_XYZ(Lab_hdr)  
array([ 0.2065400...,  0.1219722...,  0.0513695...])
>>> Lab_hdr = np.array([31.99621114, 128.00763036, 48.76952309])
>>> hdr_CIELab_to_XYZ(Lab_hdr, method='Fairchild 2010')
... 
array([ 0.2065400...,  0.1219722...,  0.0513695...])