colour.characterisation.matrix_augmented_Cheung2004#

colour.characterisation.matrix_augmented_Cheung2004(RGB: ArrayLike, terms: Literal[3, 4, 5, 7, 8, 10, 11, 14, 16, 17, 19, 20, 22, 35] | int = 3) → NDArrayFloat[source]#

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

Parameters:

  • RGB (ArrayLike) – RGB colourspace array to expand using polynomial expansion.

  • terms (Literal[3, 4, 5, 7, 8, 10, 11, 14, 16, 17, 19, 20, 22, 35] | int) – Number of terms of the expanded polynomial.

Returns:

Polynomial-expanded RGB colourspace array.

Return type:

numpy.ndarray

Notes

  • This definition combines the augmented matrices specified in [CWCR04] and [WR04].

References

[CWCR04], [WR04]

Examples

>>> RGB = np.array([0.17224810, 0.09170660, 0.06416938])
>>> matrix_augmented_Cheung2004(RGB, terms=5)
array([0.1722481..., 0.0917066..., 0.0641693..., 0.0010136..., 1...])