colour.colorimetry.yellowness_ASTMD1925#

Compute the yellowness index \(YI\) of the specified sample CIE XYZ tristimulus values using the ASTM D1925 method.

The ASTM D1925 method has been specifically developed for defining the yellowness of homogeneous, non-fluorescent, almost neutral-transparent, white-scattering or opaque plastics as they will be evaluated under daylight conditions. The method can be applied to other materials as well, provided they fit this description.

Parameters:: XYZ (Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 100]) – CIE XYZ tristimulus values of the sample.
Returns:: Yellowness index \(YI\).
Return type:: numpy.ndarray

Notes

Domain	Scale - Reference	Scale - 1
`XYZ`	100	1

Range	Scale - Reference	Scale - 1
`YI`	100	1

Input CIE XYZ tristimulus values must be adapted to CIE Illuminant C.

References

[ASTMInternational15b], [XRitePantone12]

Examples

>>> XYZ = np.array([95.00000000, 100.00000000, 105.00000000])
>>> yellowness_ASTMD1925(XYZ)
10.2999999...

colour.colorimetry.yellowness_ASTMD1925#

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