colour.yellowness

colour.yellowness(XYZ, method='ASTM E313')[source]

Returns the yellowness \(W\) using given method.

Parameters:
  • XYZ (array_like) – CIE XYZ tristimulus values of sample.
  • method (unicode, optional) – {‘ASTM E313’, ‘ASTM D1925’}, Computation method.
Returns:

yellowness \(Y\).

Return type:

numeric or ndarray

Notes

Domain Scale - Reference Scale - 1
XYZ [0, 100] [0, 1]
Range Scale - Reference Scale - 1
YI [0, 100] [0, 1]

References

[X-Rite2012a]

Examples

>>> import numpy as np
>>> XYZ = np.array([95.00000000, 100.00000000, 105.00000000])
>>> yellowness(XYZ)  # doctest: +ELLIPSIS
11.0650000...
>>> method = 'ASTM D1925'
>>> yellowness(XYZ, method=method)  # doctest: +ELLIPSIS
10.2999999...