colour.XYZ_to_JzAzBz

colour.XYZ_to_JzAzBz(XYZ_D65, constants={'b': 1.15, 'c_1': 0.8359375, 'c_2': 18.8515625, 'c_3': 18.6875, 'd': -0.56, 'd_0': 1.6295499532821565e-11, 'g': 0.66, 'm_1': 0.1593017578125, 'm_2': 134.03437499999998})[source]

Converts from CIE XYZ tristimulus values to \(J_zA_zB_z\) colourspace.

Parameters:
  • XYZ_D65 (array_like) – CIE XYZ tristimulus values under CIE Standard Illuminant D Series D65.
  • constants (Structure, optional) – \(J_zA_zB_z\) colourspace constants.
Returns:

\(J_zA_zB_z\) colourspace array where \(J_z\) is Lightness, \(A_z\) is redness-greenness and \(B_z\) is yellowness-blueness.

Return type:

ndarray

Notes

Domain Scale - Reference Scale - 1
XYZ [0, 1] [0, 1]
Range Scale - Reference Scale - 1
JzAzBz

Jz : [0, 1]

Az : [-1, 1]

Bz : [-1, 1]

Jz : [0, 1]

Az : [-1, 1]

Bz : [-1, 1]

References

[Safdar2017]

Examples

>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
>>> XYZ_to_JzAzBz(XYZ)  # doctest: +ELLIPSIS
array([ 0.0053504...,  0.0092430...,  0.0052600...])