def RGB_to_RGB(RGB,
input_colourspace,
output_colourspace,
chromatic_adaptation_method='CAT02'):
"""
Converts from given input *RGB* colourspace to output *RGB* colourspace
using given *chromatic adaptation* method.
Parameters
----------
RGB : array_like, (3,)
*RGB* colourspace matrix.
input_colourspace : RGB_Colourspace
*RGB* input colourspace.
output_colourspace : RGB_Colourspace
*RGB* output colourspace.
chromatic_adaptation_method : unicode, optional
('XYZ Scaling', 'Bradford', 'Von Kries', 'Fairchild', 'CAT02')
*Chromatic adaptation* method.
ndarray, (3,)
*RGB* colourspace matrix.
Notes
-----
- *RGB* colourspace matrices are in domain [0, 1].
Examples
--------
>>> from colour import sRGB_COLOURSPACE, PROPHOTO_RGB_COLOURSPACE
>>> RGB = np.array([0.35521588, 0.41, 0.24177934])
>>> RGB_to_RGB(
... RGB,
... sRGB_COLOURSPACE,
... PROPHOTO_RGB_COLOURSPACE) # doctest: +ELLIPSIS
array([ 0.3579334..., 0.4007138..., 0.2615704...])
"""
cat = chromatic_adaptation_matrix(
xy_to_XYZ(input_colourspace.whitepoint),
xy_to_XYZ(output_colourspace.whitepoint),
chromatic_adaptation_method)
trs_matrix = np.dot(output_colourspace.to_RGB,
np.dot(cat, input_colourspace.to_XYZ))
return np.dot(trs_matrix, RGB)
def RGB_to_RGB(RGB,
input_colourspace,
output_colourspace,
chromatic_adaptation_method='CAT02'):
"""
Converts from given input *RGB* colourspace to output *RGB* colourspace
using given *chromatic adaptation* method.
Parameters
----------
RGB : array_like, (3,)
*RGB* colourspace matrix.
input_colourspace : RGB_Colourspace
*RGB* input colourspace.
output_colourspace : RGB_Colourspace
*RGB* output colourspace.
chromatic_adaptation_method : unicode, optional
('XYZ Scaling', 'Bradford', 'Von Kries', 'Fairchild', 'CAT02')
*Chromatic adaptation* method.
ndarray, (3,)
*RGB* colourspace matrix.
Notes
-----
- *RGB* colourspace matrices are in domain [0, 1].
Examples
--------
>>> from colour import sRGB_COLOURSPACE, PROPHOTO_RGB_COLOURSPACE
>>> RGB = np.array([0.35521588, 0.41, 0.24177934])
>>> RGB_to_RGB(
... RGB,
... sRGB_COLOURSPACE,
... PROPHOTO_RGB_COLOURSPACE) # doctest: +ELLIPSIS
array([ 0.3579334..., 0.4007138..., 0.2615704...])
"""
cat = chromatic_adaptation_matrix(xy_to_XYZ(input_colourspace.whitepoint),
xy_to_XYZ(output_colourspace.whitepoint),
chromatic_adaptation_method)
trs_matrix = np.dot(output_colourspace.to_RGB,
np.dot(cat, input_colourspace.to_XYZ))
return np.dot(trs_matrix, RGB)
def XYZ_to_RGB(XYZ,
illuminant_XYZ,
illuminant_RGB,
to_RGB,
chromatic_adaptation_method='CAT02',
transfer_function=None):
"""
Converts from *CIE XYZ* colourspace to *RGB* colourspace using given
*CIE XYZ* colourspace matrix, *illuminants*, *chromatic adaptation* method,
*normalised primary matrix* and *transfer function*.
Parameters
----------
XYZ : array_like, (3,)
*CIE XYZ* colourspace matrix.
illuminant_XYZ : array_like
*CIE XYZ* colourspace *illuminant* *xy* chromaticity coordinates.
illuminant_RGB : array_like
*RGB* colourspace *illuminant* *xy* chromaticity coordinates.
to_RGB : array_like, (3, 3)
*Normalised primary matrix*.
chromatic_adaptation_method : unicode, optional
('XYZ Scaling', 'Bradford', 'Von Kries', 'Fairchild', 'CAT02')
*Chromatic adaptation* method.
transfer_function : object, optional
*Transfer function*.
Returns
-------
ndarray, (3,)
*RGB* colourspace matrix.
Notes
-----
- Input *CIE XYZ* colourspace matrix is in domain [0, 1].
- Input *illuminant_XYZ* *xy* chromaticity coordinates are in domain
[0, 1].
- Input *illuminant_RGB* *xy* chromaticity coordinates are in domain
[0, 1].
- Output *RGB* colourspace matrix is in domain [0, 1].
Examples
--------
>>> XYZ = np.array([0.1151847498, 0.1008, 0.0508937252])
>>> illuminant_XYZ = (0.34567, 0.35850)
>>> illuminant_RGB = (0.31271, 0.32902)
>>> chromatic_adaptation_method = 'Bradford'
>>> to_RGB = np.array([
... [3.24100326, -1.53739899, -0.49861587],
... [-0.96922426, 1.87592999, 0.04155422],
... [0.05563942, -0.2040112, 1.05714897]])
>>> XYZ_to_RGB(
... XYZ,
... illuminant_XYZ,
... illuminant_RGB,
... to_RGB,
... chromatic_adaptation_method) # doctest: +ELLIPSIS
array([ 0.1730350..., 0.0821103..., 0.0567249...])
"""
np.array([
[3.24100326, -1.53739899, -0.49861587],
[-0.96922426, 1.87592999, 0.04155422],
[0.05563942, -0.2040112, 1.05714897]])
cat = chromatic_adaptation_matrix(xy_to_XYZ(illuminant_XYZ),
xy_to_XYZ(illuminant_RGB),
method=chromatic_adaptation_method)
adapted_XYZ = np.dot(cat, XYZ)
RGB = np.dot(to_RGB.reshape((3, 3)), adapted_XYZ.reshape((3, 1)))
if transfer_function is not None:
RGB = np.array([transfer_function(x) for x in np.ravel(RGB)])
return np.ravel(RGB)
def RGB_to_XYZ(RGB,
illuminant_RGB,
illuminant_XYZ,
to_XYZ,
chromatic_adaptation_method='CAT02',
inverse_transfer_function=None):
"""
Converts from *RGB* colourspace to *CIE XYZ* colourspace using given
*RGB* colourspace matrix, *illuminants*, *chromatic adaptation* method,
*normalised primary matrix* and *transfer function*.
Parameters
----------
RGB : array_like, (3,)
*RGB* colourspace matrix.
illuminant_RGB : array_like
*RGB* colourspace *illuminant* chromaticity coordinates.
illuminant_XYZ : array_like
*CIE XYZ* colourspace *illuminant* chromaticity coordinates.
to_XYZ : array_like, (3, 3)
*Normalised primary matrix*.
chromatic_adaptation_method : unicode, optional
('XYZ Scaling', 'Bradford', 'Von Kries', 'Fairchild', 'CAT02')
*Chromatic adaptation* method.
inverse_transfer_function : object, optional
*Inverse transfer function*.
Returns
-------
ndarray, (3,)
*CIE XYZ* colourspace matrix.
Notes
-----
- Input *RGB* colourspace matrix is in domain [0, 1].
- Input *illuminant_RGB* *xy* chromaticity coordinates are in domain
[0, 1].
- Input *illuminant_XYZ* *xy* chromaticity coordinates are in domain
[0, 1].
- Output *CIE XYZ* colourspace matrix is in domain [0, 1].
Examples
--------
>>> RGB = np.array([0.17303501, 0.08211033, 0.05672498])
>>> illuminant_RGB = (0.31271, 0.32902)
>>> illuminant_XYZ = (0.34567, 0.35850)
>>> chromatic_adaptation_method = 'Bradford'
>>> to_XYZ = np.array([
... [0.41238656, 0.35759149, 0.18045049],
... [0.21263682, 0.71518298, 0.0721802],
... [0.01933062, 0.11919716, 0.95037259]])
>>> RGB_to_XYZ(
... RGB,
... illuminant_RGB,
... illuminant_XYZ,
... to_XYZ,
... chromatic_adaptation_method) # doctest: +ELLIPSIS
array([ 0.1151847..., 0.1008 , 0.0508937...])
"""
if inverse_transfer_function is not None:
RGB = np.array([inverse_transfer_function(x)
for x in np.ravel(RGB)])
XYZ = np.dot(to_XYZ.reshape((3, 3)), RGB.reshape((3, 1)))
cat = chromatic_adaptation_matrix(
xy_to_XYZ(illuminant_RGB),
xy_to_XYZ(illuminant_XYZ),
method=chromatic_adaptation_method)
adapted_XYZ = np.dot(cat, XYZ.reshape((3, 1)))
return np.ravel(adapted_XYZ)
def XYZ_to_RGB(XYZ,
illuminant_XYZ,
illuminant_RGB,
to_RGB,
chromatic_adaptation_method='CAT02',
transfer_function=None):
"""
Converts from *CIE XYZ* colourspace to *RGB* colourspace using given
*CIE XYZ* colourspace matrix, *illuminants*, *chromatic adaptation* method,
*normalised primary matrix* and *transfer function*.
Parameters
----------
XYZ : array_like, (3,)
*CIE XYZ* colourspace matrix.
illuminant_XYZ : array_like
*CIE XYZ* colourspace *illuminant* *xy* chromaticity coordinates.
illuminant_RGB : array_like
*RGB* colourspace *illuminant* *xy* chromaticity coordinates.
to_RGB : array_like, (3, 3)
*Normalised primary matrix*.
chromatic_adaptation_method : unicode, optional
('XYZ Scaling', 'Bradford', 'Von Kries', 'Fairchild', 'CAT02')
*Chromatic adaptation* method.
transfer_function : object, optional
*Transfer function*.
Returns
-------
ndarray, (3,)
*RGB* colourspace matrix.
Notes
-----
- Input *CIE XYZ* colourspace matrix is in domain [0, 1].
- Input *illuminant_XYZ* *xy* chromaticity coordinates are in domain
[0, 1].
- Input *illuminant_RGB* *xy* chromaticity coordinates are in domain
[0, 1].
- Output *RGB* colourspace matrix is in domain [0, 1].
Examples
--------
>>> XYZ = np.array([0.1151847498, 0.1008, 0.0508937252])
>>> illuminant_XYZ = (0.34567, 0.35850)
>>> illuminant_RGB = (0.31271, 0.32902)
>>> chromatic_adaptation_method = 'Bradford'
>>> to_RGB = np.array([
... [3.24100326, -1.53739899, -0.49861587],
... [-0.96922426, 1.87592999, 0.04155422],
... [0.05563942, -0.2040112, 1.05714897]])
>>> XYZ_to_RGB(
... XYZ,
... illuminant_XYZ,
... illuminant_RGB,
... to_RGB,
... chromatic_adaptation_method) # doctest: +ELLIPSIS
array([ 0.1730350..., 0.0821103..., 0.0567249...])
"""
np.array([[3.24100326, -1.53739899, -0.49861587],
[-0.96922426, 1.87592999, 0.04155422],
[0.05563942, -0.2040112, 1.05714897]])
cat = chromatic_adaptation_matrix(xy_to_XYZ(illuminant_XYZ),
xy_to_XYZ(illuminant_RGB),
method=chromatic_adaptation_method)
adapted_XYZ = np.dot(cat, XYZ)
RGB = np.dot(to_RGB.reshape((3, 3)), adapted_XYZ.reshape((3, 1)))
if transfer_function is not None:
RGB = np.array([transfer_function(x) for x in np.ravel(RGB)])
return np.ravel(RGB)
def RGB_to_XYZ(RGB,
illuminant_RGB,
illuminant_XYZ,
to_XYZ,
chromatic_adaptation_method='CAT02',
inverse_transfer_function=None):
"""
Converts from *RGB* colourspace to *CIE XYZ* colourspace using given
*RGB* colourspace matrix, *illuminants*, *chromatic adaptation* method,
*normalised primary matrix* and *transfer function*.
Parameters
----------
RGB : array_like, (3,)
*RGB* colourspace matrix.
illuminant_RGB : array_like
*RGB* colourspace *illuminant* chromaticity coordinates.
illuminant_XYZ : array_like
*CIE XYZ* colourspace *illuminant* chromaticity coordinates.
to_XYZ : array_like, (3, 3)
*Normalised primary matrix*.
chromatic_adaptation_method : unicode, optional
('XYZ Scaling', 'Bradford', 'Von Kries', 'Fairchild', 'CAT02')
*Chromatic adaptation* method.
inverse_transfer_function : object, optional
*Inverse transfer function*.
Returns
-------
ndarray, (3,)
*CIE XYZ* colourspace matrix.
Notes
-----
- Input *RGB* colourspace matrix is in domain [0, 1].
- Input *illuminant_RGB* *xy* chromaticity coordinates are in domain
[0, 1].
- Input *illuminant_XYZ* *xy* chromaticity coordinates are in domain
[0, 1].
- Output *CIE XYZ* colourspace matrix is in domain [0, 1].
Examples
--------
>>> RGB = np.array([0.17303501, 0.08211033, 0.05672498])
>>> illuminant_RGB = (0.31271, 0.32902)
>>> illuminant_XYZ = (0.34567, 0.35850)
>>> chromatic_adaptation_method = 'Bradford'
>>> to_XYZ = np.array([
... [0.41238656, 0.35759149, 0.18045049],
... [0.21263682, 0.71518298, 0.0721802],
... [0.01933062, 0.11919716, 0.95037259]])
>>> RGB_to_XYZ(
... RGB,
... illuminant_RGB,
... illuminant_XYZ,
... to_XYZ,
... chromatic_adaptation_method) # doctest: +ELLIPSIS
array([ 0.1151847..., 0.1008 , 0.0508937...])
"""
if inverse_transfer_function is not None:
RGB = np.array([inverse_transfer_function(x) for x in np.ravel(RGB)])
XYZ = np.dot(to_XYZ.reshape((3, 3)), RGB.reshape((3, 1)))
cat = chromatic_adaptation_matrix(xy_to_XYZ(illuminant_RGB),
xy_to_XYZ(illuminant_XYZ),
method=chromatic_adaptation_method)
adapted_XYZ = np.dot(cat, XYZ.reshape((3, 1)))
return np.ravel(adapted_XYZ)
def test_chromatic_adaptation_matrix(self):
"""
Tests :func:`colour.adaptation.cat.chromatic_adaptation_matrix`
definition.
"""
numpy.testing.assert_almost_equal(
chromatic_adaptation_matrix(
numpy.array([1.09923822, 1.000, 0.35445412]),
numpy.array([0.96907232, 1.000, 1.121792157])),
numpy.array(
[0.87145615, -0.13204674, 0.40394832,
-0.09638805, 1.04909781, 0.1604033,
0.0080207, 0.02826367, 3.06023194]).reshape((3, 3)),
decimal=7)
numpy.testing.assert_almost_equal(
chromatic_adaptation_matrix(
numpy.array([1.92001986, 1, -0.1241347]),
numpy.array([1.0131677, 1.000, 2.11217686])),
numpy.array(
[0.91344833, -1.20588903, -3.74768526,
-0.81680514, 2.3858187, -1.46988227,
-0.05367575, -0.31122239, -20.35255049]).reshape((3, 3)),
decimal=7)
numpy.testing.assert_almost_equal(
chromatic_adaptation_matrix(
numpy.array([1.92001986, 1, -0.1241347]),
numpy.array([1.0131677, 1.000, 2.11217686])),
numpy.linalg.inv(chromatic_adaptation_matrix(
numpy.array([1.0131677, 1.000, 2.11217686]),
numpy.array([1.92001986, 1., -0.1241347]))))
numpy.testing.assert_almost_equal(
chromatic_adaptation_matrix(
numpy.array([1.09850, 1.00000, 0.35585]),
numpy.array([0.99072, 1.00000, 0.85223]),
method='XYZ Scaling'),
numpy.array([0.90188439, 0., 0.,
0., 1., 0.,
0., 0., 2.39491359]).reshape((3, 3)),
decimal=7)
numpy.testing.assert_almost_equal(
chromatic_adaptation_matrix(
numpy.array([1.09850, 1.00000, 0.35585]),
numpy.array([0.99072, 1.00000, 0.85223]),
method='Bradford'),
numpy.array(
[0.89051629, -0.08291357, 0.26809449,
-0.09715236, 1.07542618, 0.08794629,
0.05389701, -0.09085576, 2.48385527]).reshape((3, 3)),
decimal=7)
numpy.testing.assert_almost_equal(
chromatic_adaptation_matrix(
numpy.array([1.09850, 1.00000, 0.35585]),
numpy.array([0.99072, 1.00000, 0.85223]),
method='Von Kries'),
numpy.array(
[0.9574884, -0.16436134, 0.29023559,
-0.01805393, 1.01853791, 0.00363729,
0., 0., 2.39491359]).reshape((3, 3)),
decimal=7)
