colour.adaptation.vonkries Module¶
Von Kries Chromatic Adaptation Model¶
Defines Von Kries chromatic adaptation model objects:
References
[1] | Fairchild, M. D. (2013). Chromatic Adaptation Models. In Color Appearance Models (3rd ed., pp. 4179–4252). Wiley. ASIN:B00DAYO8E2 |
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colour.adaptation.vonkries.
chromatic_adaptation_matrix_VonKries
(XYZ_w, XYZ_wr, transform=u'CAT02')[source]¶ Computes the chromatic adaptation matrix from test viewing conditions to reference viewing conditions.
Parameters: - XYZ_w (array_like) – Test viewing condition CIE XYZ tristimulus values of whitepoint.
- XYZ_wr (array_like) – Reference viewing condition CIE XYZ tristimulus values of whitepoint.
- transform (unicode, optional) – {‘CAT02’, ‘XYZ Scaling’, ‘Von Kries’, ‘Bradford’, ‘Sharp’, ‘Fairchild, ‘CMCCAT97’, ‘CMCCAT2000’, ‘CAT02_BRILL_CAT’, ‘Bianco’, ‘Bianco PC’}, Chromatic adaptation transform.
Returns: Chromatic adaptation matrix.
Return type: ndarray
Raises: KeyError
– If chromatic adaptation method is not defined.Examples
>>> XYZ_w = np.array([1.09846607, 1.00000000, 0.35582280]) >>> XYZ_wr = np.array([0.95042855, 1.00000000, 1.08890037]) >>> chromatic_adaptation_matrix_VonKries( ... XYZ_w, XYZ_wr) array([[ 0.8687653..., -0.1416539..., 0.3871961...], [-0.1030072..., 1.0584014..., 0.1538646...], [ 0.0078167..., 0.0267875..., 2.9608177...]])
Using Bradford method:
>>> XYZ_w = np.array([1.09846607, 1.00000000, 0.35582280]) >>> XYZ_wr = np.array([0.95042855, 1.00000000, 1.08890037]) >>> method = 'Bradford' >>> chromatic_adaptation_matrix_VonKries( ... XYZ_w, XYZ_wr, method) array([[ 0.8446794..., -0.1179355..., 0.3948940...], [-0.1366408..., 1.1041236..., 0.1291981...], [ 0.0798671..., -0.1349315..., 3.1928829...]])
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colour.adaptation.vonkries.
chromatic_adaptation_VonKries
(XYZ, XYZ_w, XYZ_wr, transform=u'CAT02')[source]¶ Adapts given stimulus from test viewing conditions to reference viewing conditions.
Parameters: - XYZ (array_like) – CIE XYZ tristimulus values of stimulus to adapt.
- XYZ_w (array_like) – Test viewing condition CIE XYZ tristimulus values of whitepoint.
- XYZ_wr (array_like) – Reference viewing condition CIE XYZ tristimulus values of whitepoint.
- transform (unicode, optional) – {‘CAT02’, ‘XYZ Scaling’, ‘Von Kries’, ‘Bradford’, ‘Sharp’, ‘Fairchild, ‘CMCCAT97’, ‘CMCCAT2000’, ‘CAT02_BRILL_CAT’, ‘Bianco’, ‘Bianco PC’}, Chromatic adaptation transform.
Returns: CIE XYZ_c tristimulus values of the stimulus corresponding colour.
Return type: ndarray
Examples
>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313]) >>> XYZ_w = np.array([1.09846607, 1.00000000, 0.35582280]) >>> XYZ_wr = np.array([0.95042855, 1.00000000, 1.08890037]) >>> chromatic_adaptation_VonKries(XYZ, XYZ_w, XYZ_wr) array([ 0.0839746..., 0.1141321..., 0.2862554...])
Using Bradford method:
>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313]) >>> XYZ_w = np.array([1.09846607, 1.00000000, 0.35582280]) >>> XYZ_wr = np.array([0.95042855, 1.00000000, 1.08890037]) >>> method = 'Bradford' >>> chromatic_adaptation_VonKries( ... XYZ, XYZ_w, XYZ_wr, method) array([ 0.0854032..., 0.1140122..., 0.2972149...])