colour.colorimetry.whiteness_Berger1959

colour.colorimetry.whiteness_Berger1959(XYZ, XYZ_0)[source]

Returns the whiteness index \(WI\) of given sample CIE XYZ tristimulus values using Berger (1959) method.

Parameters:
  • XYZ (array_like) – CIE XYZ tristimulus values of sample.
  • XYZ_0 (array_like) – CIE XYZ tristimulus values of reference white.
Returns:

Whiteness \(WI\).

Return type:

numeric or ndarray

Notes

  • Input CIE XYZ and CIE XYZ_0 tristimulus values are in domain [0, 100].
  • Whiteness \(WI\) values larger than 33.33 indicate a bluish white and values smaller than 33.33 indicate a yellowish white.

Warning

The input domain of that definition is non standard!

References

Examples

>>> XYZ = np.array([95.00000000, 100.00000000, 105.00000000])
>>> XYZ_0 = np.array([94.80966767, 100.00000000, 107.30513595])
>>> whiteness_Berger1959(XYZ, XYZ_0)  
30.3638017...