colour.colorimetry.yellowness_ASTME313

colour.colorimetry.yellowness_ASTME313(XYZ, C_XZ=array([1.2985, 1.1335]))[source]

Returns the yellowness index \(YI\) of given sample CIE XYZ tristimulus values using ASTM E313 method.

ASTM E313 has successfully been used for a variety of white or near white materials. This includes coatings, plastics, textiles.

Parameters
  • XYZ (array_like) – CIE XYZ tristimulus values of sample.

  • C_XZ (array_like, optional) – 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

Whiteness \(YI\).

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]

Examples

>>> XYZ = np.array([95.00000000, 100.00000000, 105.00000000])
>>> yellowness_ASTME313(XYZ)  
4.3400000...