colour.hdr_CIELab_to_XYZ#

colour.hdr_CIELab_to_XYZ(Lab_hdr: ArrayLike, illuminant: ArrayLike = CCS_ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65'], Y_s: ArrayLike = 0.2, Y_abs: ArrayLike = 100, method: Literal['Fairchild 2011', 'Fairchild 2010'] | str = 'Fairchild 2011') NDArrayFloat[source]#

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

Parameters:
  • Lab_hdr (ArrayLike) – hdr-CIELAB colourspace array.

  • illuminant (ArrayLike) – Reference illuminant CIE xy chromaticity coordinates or CIE xyY colourspace array.

  • Y_s (ArrayLike) – Relative luminance \(Y_s\) of the surround.

  • Y_abs (ArrayLike) – Absolute luminance \(Y_{abs}\) of the scene diffuse white in \(cd/m^2\).

  • method (Literal['Fairchild 2011', 'Fairchild 2010'] | str) – Computation method.

Returns:

CIE XYZ tristimulus values.

Return type:

numpy.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...])