colour.Hunter_Rdab_to_XYZ¶
-
colour.
Hunter_Rdab_to_XYZ
(R_d_ab, XYZ_n=array([ 95.02, 100., 108.82]), K_ab=array([ 172.3, 67.2]))[source]¶ Converts from Hunter Rd,a,b colour scale to CIE XYZ tristimulus values.
Parameters: - R_d_ab (array_like) – Hunter Rd,a,b colour scale array.
- XYZ_n (array_like, optional) – Reference illuminant tristimulus values.
- K_ab (array_like, optional) – Reference illuminant chromaticity coefficients, if
K_ab
is set to None it will be computed usingcolour.XYZ_to_K_ab_HunterLab1966()
.
Returns: CIE XYZ tristimulus values.
Return type: 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
Examples
>>> import numpy as np >>> R_d_ab = np.array([12.19722500, 57.12537874, 17.46241341]) >>> D65 = HUNTERLAB_ILLUMINANTS[ ... '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])