colour.yellowness

colour.yellowness(XYZ, method='ASTM E313', **kwargs)[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’, ‘ASTM E313 Alternative’}, Computation method.

Other Parameters

C_XZ (array_like, optional) – {colour.colorimetry.yellowness_ASTME313()}, Coefficients \(C_X\) and \(C_Z\) for the CIE 1931 2 Degree Standard Observer and CIE 1964 10 Degree Standard Observer and CIE Illuminant C and CIE Standard Illuminant D65.

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

[ASTMInternational15b], [XRitePantone12]

Examples

>>> XYZ = np.array([95.00000000, 100.00000000, 105.00000000])
>>> yellowness(XYZ)  
4.3400000...
>>> yellowness(XYZ, method='ASTM E313 Alternative')  
11.0650000...
>>> yellowness(XYZ, method='ASTM D1925')  
10.2999999...