colour.Hunter_Rdab_to_XYZ#

colour.Hunter_Rdab_to_XYZ(R_d_ab: ArrayLike, XYZ_n: ArrayLike = TVS_ILLUMINANTS_HUNTERLAB['CIE 1931 2 Degree Standard Observer']['D65'].XYZ_n, K_ab: ArrayLike = TVS_ILLUMINANTS_HUNTERLAB['CIE 1931 2 Degree Standard Observer']['D65'].K_ab) → NDArrayFloat[source]#

Convert from Hunter Rd,a,b colour scale to CIE XYZ tristimulus values.

Parameters:

  • R_d_ab (ArrayLike) – Hunter Rd,a,b colour scale array.

  • XYZ_n (ArrayLike) – Reference illuminant tristimulus values.

  • K_ab (ArrayLike) – Reference illuminant chromaticity coefficients, if K_ab is set to None it will be computed using colour.XYZ_to_K_ab_HunterLab1966().

Returns:

CIE XYZ tristimulus values.

Return type:

numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

R_d_ab

R_d : [0, 100]

a_Rd : [-100, 100]

b_Rd : [-100, 100]

R_d : [0, 1]

a_Rd : [-1, 1]

b_Rd : [-1, 1]

XYZ_n

[0, 100]

[0, 1]

Range

Scale - Reference

Scale - 1

XYZ

[0, 100]

[0, 1]

References

[HunterLab12]

Examples

>>> import numpy as np
>>> R_d_ab = np.array([12.19722500, 57.12537874, 17.46241341])
>>> D65 = TVS_ILLUMINANTS_HUNTERLAB["CIE 1931 2 Degree Standard Observer"][
...     "D65"
... ]
>>> Hunter_Rdab_to_XYZ(R_d_ab, D65.XYZ_n, D65.K_ab)
array([ 20.654008,  12.197225,   5.136952])