colour.XYZ_to_Hunter_Rdab¶
-
colour.
XYZ_to_Hunter_Rdab
(XYZ, XYZ_n=array([ 95.02, 100., 108.82]), K_ab=array([ 172.3, 67.2]))[source]¶ Converts from CIE XYZ tristimulus values to Hunter Rd,a,b colour scale.
Parameters: - XYZ (array_like) – CIE XYZ tristimulus values.
- 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: Hunter Rd,a,b colour scale array.
Return type: ndarray
Notes
Domain Scale - Reference Scale - 1 XYZ
[0, 100] [0, 1] XYZ_n
[0, 100] [0, 1] Range 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]References
Examples
>>> import numpy as np >>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952]) * 100 >>> D65 = HUNTERLAB_ILLUMINANTS[ ... 'CIE 1931 2 Degree Standard Observer']['D65'] >>> XYZ_to_Hunter_Rdab(XYZ, D65.XYZ_n, D65.K_ab) ... # doctest: +ELLIPSIS array([ 12.197225 ..., 57.1253787..., 17.4624134...])