colour.XYZ_to_Lab

colour.XYZ_to_Lab(XYZ, illuminant=array([ 0.3457, 0.3585]))

Converts from CIE XYZ tristimulus values to CIE L*a*b* colourspace.

Parameters:

• XYZ (array_like) – CIE XYZ tristimulus values.
• illuminant (array_like, optional) – Reference illuminant xy chromaticity coordinates or CIE xyY colourspace array.

Returns:

CIE L*a*b* colourspace array.

Return type:

ndarray

Notes

• Input CIE XYZ tristimulus values are in domain [0, 1].
• Input illuminant xy chromaticity coordinates or CIE xyY colourspace array are in domain [0, \(\infty\)].
• Output Lightness \(L^*\) is in range [0, 100].

References

• [CIET14804f]

Examples

>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313])
>>> XYZ_to_Lab(XYZ)  
array([ 37.9856291..., -23.6290768...,  -4.4174661...])