colour.colorimetry.yellowness_ASTMD1925¶

colour.colorimetry.yellowness_ASTMD1925(XYZ)[source]¶

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

ASTM D1925 has been specifically developed for the definition of the Yellowness of homogeneous, non-fluorescent, almost neutral-transparent, white-scattering or opaque plastics as they will be reviewed under daylight condition. It can be other materials as well, as long as they fit into this description.

Parameters:	XYZ (array_like) – CIE XYZ tristimulus values of sample.
Returns:	Whiteness \(YI\).
Return type:	numeric or ndarray

Warning

The input domain of that definition is non standard!

Notes

Input CIE XYZ tristimulus values are in domain [0, 100].

References

[XRP12]

Examples

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