colour.characterisation.augmented_matrix_Cheung2004

colour.characterisation.augmented_matrix_Cheung2004(RGB, terms=3)[source]

Performs polynomial expansion of given RGB colourspace array using Cheung et al. (2004) method.

Parameters:
  • RGB (array_like) – RGB colourspace array to expand.
  • terms (int, optional) – Number of terms of the expanded polynomial, must be one of [3, 5, 7, 8, 10, 11, 14, 16, 17, 19, 20, 22].
Returns:

Expanded RGB colourspace array.

Return type:

ndarray

Notes

References

[Cheung2004], [Westland2004]

Examples

>>> RGB = np.array([0.17224810, 0.09170660, 0.06416938])
>>> augmented_matrix_Cheung2004(RGB, terms=5)  # doctest: +ELLIPSIS
array([ 0.1722481...,  0.0917066...,  0.0641693...,  0.0010136...,  1...])