colour.XYZ_to_CIECAM02¶
- colour.XYZ_to_CIECAM02(XYZ: ArrayLike, XYZ_w: ArrayLike, L_A: FloatingOrArrayLike, Y_b: FloatingOrArrayLike, surround: colour.appearance.ciecam02.InductionFactors_CIECAM02 = VIEWING_CONDITIONS_CIECAM02['Average'], discount_illuminant: bool = False) colour.appearance.ciecam02.CAM_Specification_CIECAM02[source]¶
Compute the CIECAM02 colour appearance model correlates from given CIE XYZ tristimulus values.
- Parameters
XYZ (ArrayLike) – CIE XYZ tristimulus values of test sample / stimulus.
XYZ_w (ArrayLike) – CIE XYZ tristimulus values of reference white.
L_A (FloatingOrArrayLike) – Adapting field luminance \(L_A\) in \(cd/m^2\), (often taken to be 20% of the luminance of a white object in the scene).
Y_b (FloatingOrArrayLike) – Luminous factor of background \(Y_b\) such as \(Y_b = 100 x L_b / L_w\) where \(L_w\) is the luminance of the light source and \(L_b\) is the luminance of the background. For viewing images, \(Y_b\) can be the average \(Y\) value for the pixels in the entire image, or frequently, a \(Y\) value of 20, approximate an \(L^*\) of 50 is used.
surround (colour.appearance.ciecam02.InductionFactors_CIECAM02) – Surround viewing conditions induction factors.
discount_illuminant (bool) – Truth value indicating if the illuminant should be discounted.
- Returns
CIECAM02 colour appearance model specification.
- Return type
Notes
Domain
Scale - Reference
Scale - 1
XYZ[0, 100]
[0, 1]
XYZ_w[0, 100]
[0, 1]
Range
Scale - Reference
Scale - 1
CAM_Specification_CIECAM02.J[0, 100]
[0, 1]
CAM_Specification_CIECAM02.C[0, 100]
[0, 1]
CAM_Specification_CIECAM02.h[0, 360]
[0, 1]
CAM_Specification_CIECAM02.s[0, 100]
[0, 1]
CAM_Specification_CIECAM02.Q[0, 100]
[0, 1]
CAM_Specification_CIECAM02.M[0, 100]
[0, 1]
CAM_Specification_CIECAM02.H[0, 400]
[0, 1]
References
[Fai04], [LL13], [MFH+02], [Wikipedia07b]
Examples
>>> XYZ = np.array([19.01, 20.00, 21.78]) >>> XYZ_w = np.array([95.05, 100.00, 108.88]) >>> L_A = 318.31 >>> Y_b = 20.0 >>> surround = VIEWING_CONDITIONS_CIECAM02['Average'] >>> XYZ_to_CIECAM02(XYZ, XYZ_w, L_A, Y_b, surround) CAM_Specification_CIECAM02(J=41.7310911..., C=0.1047077..., h=219.0484326..., s=2.3603053..., Q=195.3713259..., M=0.1088421..., H=278.0607358..., HC=None)