colour.DIN99_to_XYZ

colour.DIN99_to_XYZ(Lab_99, illuminant=array([0.3127, 0.329]), k_E=1, k_CH=1, method='DIN99')[source]

Converts from DIN99 colourspace or one of the DIN99b, DIN99c, DIN99d refined formulas according to Cui et al. (2002) to CIE XYZ tristimulus values.

Parameters
  • Lab_99 (array_like) – DIN99 colourspace array.

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

  • k_E (numeric, optional) – Parametric factor \(K_E\) used to compensate for texture and other specimen presentation effects.

  • k_CH (numeric, optional) – Parametric factor \(K_{CH}\) used to compensate for texture and other specimen presentation effects.

  • method (str, optional) – {‘DIN99’, ‘ASTMD2244-07’, ‘DIN99b’, ‘DIN99c’, ‘DIN99d’}, Computation method to choose between the [ASTMInternational07] formula and the refined formulas according to Cui et al. (2002).

Returns

CIE XYZ tristimulus values.

Return type

ndarray

Notes

Domain

Scale - Reference

Scale - 1

Lab_99

L_99 : [0, 100]

a_99 : [-100, 100]

b_99 : [-100, 100]

L_99 : [0, 1]

a_99 : [-1, 1]

b_99 : [-1, 1]

illuminant

[0, 1]

[0, 1]

Range

Scale - Reference

Scale - 1

XYZ

[0, 1]

[0, 1]

References

[ASTMInternational07]

Examples

>>> import numpy as np
>>> Lab_99 = np.array([53.22821989, 28.41634656, 3.89839552])
>>> DIN99_to_XYZ(Lab_99)  
array([ 0.2065400...,  0.1219722...,  0.0513695...])