def test_nan_xy_to_UCS_uv(self):
"""
Tests :func:`colour.models.cie_ucs.xy_to_UCS_uv` definition nan
support.
"""
cases = [-1.0, 0.0, 1.0, -np.inf, np.inf, np.nan]
cases = set(permutations(cases * 3, r=2))
for case in cases:
xy = np.array(case)
xy_to_UCS_uv(xy)
def xy_to_ij(xy):
"""
Converts given *xy* chromaticity coordinates to *ij* chromaticity
coordinates.
"""
return xy_to_UCS_uv(xy)
def xy_to_ij(xy):
"""
Converts given *xy* chromaticity coordinates to *ij* chromaticity
coordinates.
"""
return xy_to_UCS_uv(xy)
def test_n_dimensional_xy_to_UCS_uv(self):
"""
Tests :func:`colour.models.cie_ucs.xy_to_UCS_uv` definition
n-dimensional arrays support.
"""
xy = np.array([0.54369555, 0.32107941])
uv = xy_to_UCS_uv(xy)
xy = np.tile(xy, (6, 1))
uv = np.tile(uv, (6, 1))
np.testing.assert_almost_equal(xy_to_UCS_uv(xy), uv, decimal=7)
xy = np.reshape(xy, (2, 3, 2))
uv = np.reshape(uv, (2, 3, 2))
np.testing.assert_almost_equal(xy_to_UCS_uv(xy), uv, decimal=7)
def test_xy_to_UCS_uv(self):
"""
Tests :func:`colour.models.cie_ucs.xy_to_UCS_uv` definition.
"""
np.testing.assert_almost_equal(xy_to_UCS_uv(
np.array([0.54369555, 0.32107941])),
np.array([0.37720213, 0.33413508]),
decimal=7)
np.testing.assert_almost_equal(xy_to_UCS_uv(
np.array([0.29777734, 0.48246445])),
np.array([0.14536327, 0.35328046]),
decimal=7)
np.testing.assert_almost_equal(xy_to_UCS_uv(
np.array([0.18582823, 0.14633764])),
np.array([0.16953602, 0.20026156]),
decimal=7)
def XYZ_to_UVW(
XYZ,
illuminant=ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65']):
"""
Converts from *CIE XYZ* tristimulus values to *CIE 1964 U\\*V\\*W\\**
colourspace.
Parameters
----------
XYZ : array_like
*CIE XYZ* tristimulus values.
illuminant : array_like, optional
Reference *illuminant* *xy* chromaticity coordinates or *CIE xyY*
colourspace array.
Returns
-------
ndarray
*CIE 1964 U\\*V\\*W\\** colourspace array.
Warning
-------
The input domain and output range of that definition are non standard!
Notes
-----
+----------------+-----------------------+-----------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``XYZ`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
| ``illuminant`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
+----------------+-----------------------+-----------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``UVW`` | ``U`` : [-100, 100] | ``U`` : [-1, 1] |
| | | |
| | ``V`` : [-100, 100] | ``V`` : [-1, 1] |
| | | |
| | ``W`` : [0, 100] | ``W`` : [0, 1] |
+----------------+-----------------------+-----------------+
References
----------
:cite:`Wikipedia2008a`
Examples
--------
>>> import numpy as np
>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952]) * 100
>>> XYZ_to_UVW(XYZ) # doctest: +ELLIPSIS
array([ 94.5503572..., 11.5553652..., 40.5475740...])
"""
XYZ = to_domain_100(XYZ)
xy = xyY_to_xy(illuminant)
xyY = XYZ_to_xyY(XYZ, xy)
_x, _y, Y = tsplit(xyY)
u, v = tsplit(UCS_to_uv(XYZ_to_UCS(XYZ)))
u_0, v_0 = tsplit(xy_to_UCS_uv(xy))
W = 25 * spow(Y, 1 / 3) - 17
U = 13 * W * (u - u_0)
V = 13 * W * (v - v_0)
UVW = tstack([U, V, W])
return from_range_100(UVW)
def UVW_to_XYZ(
UVW,
illuminant=ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65']):
"""
Converts *CIE 1964 U\\*V\\*W\\** colourspace to *CIE XYZ* tristimulus
values.
Parameters
----------
UVW : array_like
*CIE 1964 U\\*V\\*W\\** colourspace array.
illuminant : array_like, optional
Reference *illuminant* *xy* chromaticity coordinates or *CIE xyY*
colourspace array.
Returns
-------
ndarray
*CIE XYZ* tristimulus values.
Warning
-------
The input domain and output range of that definition are non standard!
Notes
-----
+----------------+-----------------------+-----------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``UVW`` | ``U`` : [-100, 100] | ``U`` : [-1, 1] |
| | | |
| | ``V`` : [-100, 100] | ``V`` : [-1, 1] |
| | | |
| | ``W`` : [0, 100] | ``W`` : [0, 1] |
+----------------+-----------------------+-----------------+
| ``illuminant`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
+----------------+-----------------------+-----------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``XYZ`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
References
----------
:cite:`Wikipedia2008a`
Examples
--------
>>> import numpy as np
>>> UVW = np.array([94.55035725, 11.55536523, 40.54757405])
>>> UVW_to_XYZ(UVW)
array([ 20.654008, 12.197225, 5.136952])
"""
U, V, W = tsplit(to_domain_100(UVW))
u_0, v_0 = tsplit(xy_to_UCS_uv(xyY_to_xy(illuminant)))
Y = ((W + 17) / 25)**3
u = U / (13 * W) + u_0
v = V / (13 * W) + v_0
x, y = tsplit(UCS_uv_to_xy(tstack([u, v])))
XYZ = xyY_to_XYZ(tstack([x, y, Y]))
return from_range_100(XYZ)
def XYZ_to_UVW(
XYZ,
illuminant=ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65']):
"""
Converts from *CIE XYZ* tristimulus values to *CIE 1964 U\\*V\\*W\\**
colourspace.
Parameters
----------
XYZ : array_like
*CIE XYZ* tristimulus values.
illuminant : array_like, optional
Reference *illuminant* *xy* chromaticity coordinates or *CIE xyY*
colourspace array.
Returns
-------
ndarray
*CIE 1964 U\\*V\\*W\\** colourspace array.
Warning
-------
The input domain and output range of that definition are non standard!
Notes
-----
+----------------+-----------------------+-----------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``XYZ`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
| ``illuminant`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
+----------------+-----------------------+-----------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``UVW`` | ``U`` : [-100, 100] | ``U`` : [-1, 1] |
| | | |
| | ``V`` : [-100, 100] | ``V`` : [-1, 1] |
| | | |
| | ``W`` : [0, 100] | ``W`` : [0, 1] |
+----------------+-----------------------+-----------------+
References
----------
:cite:`Wikipedia2008a`
Examples
--------
>>> import numpy as np
>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952]) * 100
>>> XYZ_to_UVW(XYZ) # doctest: +ELLIPSIS
array([ 94.5503572..., 11.5553652..., 40.5475740...])
"""
XYZ = to_domain_100(XYZ)
xy = xyY_to_xy(illuminant)
xyY = XYZ_to_xyY(XYZ, xy)
_x, _y, Y = tsplit(xyY)
u, v = tsplit(UCS_to_uv(XYZ_to_UCS(XYZ)))
u_0, v_0 = tsplit(xy_to_UCS_uv(xy))
W = 25 * spow(Y, 1 / 3) - 17
U = 13 * W * (u - u_0)
V = 13 * W * (v - v_0)
UVW = tstack([U, V, W])
return from_range_100(UVW)
def UVW_to_XYZ(
UVW,
illuminant=ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65']):
"""
Converts *CIE 1964 U\\*V\\*W\\** colourspace to *CIE XYZ* tristimulus
values.
Parameters
----------
UVW : array_like
*CIE 1964 U\\*V\\*W\\** colourspace array.
illuminant : array_like, optional
Reference *illuminant* *xy* chromaticity coordinates or *CIE xyY*
colourspace array.
Returns
-------
ndarray
*CIE XYZ* tristimulus values.
Warning
-------
The input domain and output range of that definition are non standard!
Notes
-----
+----------------+-----------------------+-----------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``UVW`` | ``U`` : [-100, 100] | ``U`` : [-1, 1] |
| | | |
| | ``V`` : [-100, 100] | ``V`` : [-1, 1] |
| | | |
| | ``W`` : [0, 100] | ``W`` : [0, 1] |
+----------------+-----------------------+-----------------+
| ``illuminant`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
+----------------+-----------------------+-----------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+================+=======================+=================+
| ``XYZ`` | [0, 1] | [0, 1] |
+----------------+-----------------------+-----------------+
References
----------
:cite:`Wikipedia2008a`
Examples
--------
>>> import numpy as np
>>> UVW = np.array([94.55035725, 11.55536523, 40.54757405])
>>> UVW_to_XYZ(UVW)
array([ 20.654008, 12.197225, 5.136952])
"""
U, V, W = tsplit(to_domain_100(UVW))
u_0, v_0 = tsplit(xy_to_UCS_uv(xyY_to_xy(illuminant)))
Y = ((W + 17) / 25) ** 3
u = U / (13 * W) + u_0
v = V / (13 * W) + v_0
x, y = tsplit(UCS_uv_to_xy(tstack([u, v])))
XYZ = xyY_to_XYZ(tstack([x, y, Y]))
return from_range_100(XYZ)
