def test_domain_range_scale_CAM16_to_XYZ(self):
"""
Tests :func:`colour.appearance.cam16.CAM16_to_XYZ` definition domain
and range scale support.
"""
XYZ_i = 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 = CAM16_VIEWING_CONDITIONS['Average']
specification = XYZ_to_CAM16(XYZ_i, XYZ_w, L_A, Y_b, surround)
XYZ = CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround)
d_r = (
('reference', 1, 1, 1),
(1, np.array([1, 1, 1 / 360, 1, 1, 1, 1 / 360]), 0.01, 0.01),
(100, np.array([1, 1, 100 / 360, 1, 1, 1, 100 / 360]), 1, 1),
)
for scale, factor_a, factor_b, factor_c in d_r:
with domain_range_scale(scale):
np.testing.assert_almost_equal(CAM16_to_XYZ(
specification[:-1] * factor_a, XYZ_w * factor_b, L_A, Y_b,
surround),
XYZ * factor_c,
decimal=7)
def test_CAM16_to_XYZ(self):
"""Test :func:`colour.appearance.cam16.CAM16_to_XYZ` definition."""
specification = CAM_Specification_CAM16(41.73120791, 0.10335574,
217.06795977)
XYZ_w = np.array([95.05, 100.00, 108.88])
L_A = 318.31
Y_b = 20
surround = VIEWING_CONDITIONS_CAM16["Average"]
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
np.array([19.01, 20.00, 21.78]),
decimal=7,
)
specification = CAM_Specification_CAM16(65.42828069, 49.67956420,
17.48659243)
L_A = 31.83
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
np.array([57.06, 43.06, 31.96]),
decimal=7,
)
specification = CAM_Specification_CAM16(21.36052893, 50.99381895,
178.86724266)
XYZ_w = np.array([109.85, 100, 35.58])
L_A = 318.31
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
np.array([3.53, 6.56, 2.14]),
decimal=7,
)
specification = CAM_Specification_CAM16(41.36326063, 52.81154022,
258.88676291)
L_A = 318.31
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
np.array([19.01, 20.00, 21.78]),
decimal=7,
)
specification = CAM_Specification_CAM16(21.03801957, 457.78881613,
350.06445098)
XYZ_w = np.array([95.05, 100.00, 108.88])
L_A = 4.074366543152521
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
np.array([61.45276998, 7.00421901, 82.2406738]),
decimal=7,
)
def test_domain_range_scale_CAM16_to_XYZ(self):
"""
Test :func:`colour.appearance.cam16.CAM16_to_XYZ` definition domain
and range scale support.
"""
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
surround = VIEWING_CONDITIONS_CAM16["Average"]
specification = XYZ_to_CAM16(XYZ, XYZ_w, L_A, Y_b, surround)
XYZ = CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround)
d_r = (
("reference", 1, 1),
(
"1",
np.array([
1 / 100,
1 / 100,
1 / 360,
1 / 100,
1 / 100,
1 / 100,
1 / 400,
np.nan,
]),
0.01,
),
(
"100",
np.array([1, 1, 100 / 360, 1, 1, 1, 100 / 400, np.nan]),
1,
),
)
for scale, factor_a, factor_b in d_r:
with domain_range_scale(scale):
np.testing.assert_almost_equal(
CAM16_to_XYZ(
specification * factor_a,
XYZ_w * factor_b,
L_A,
Y_b,
surround,
),
XYZ * factor_b,
decimal=7,
)
def _XYZ_from_data(self, data, correlates):
"""
Returns the *CIE XYZ* tristimulus values from given *CAM16* colour
appearance model input data.
Parameters
----------
data : list
Fixture data.
correlates : array_like
Correlates used to build the input *CAM16* colour appearance
model specification.
Returns
-------
array_like
*CIE XYZ* tristimulus values
"""
XYZ_w = tstack([data['X_w'], data['Y_w'], data['Z_w']])
i, j, k = correlates
CAM16_specification = as_namedtuple(
{
i: data[i],
j: data[j],
k: data[k]
}, CAM16_Specification)
XYZ = CAM16_to_XYZ(
CAM16_specification, XYZ_w, data['L_A'], data['Y_b'],
CAM16_InductionFactors(data['F'], data['c'], data['N_c']))
return XYZ
def test_n_dimensional_CAM16_to_XYZ(self):
"""
Test :func:`colour.appearance.cam16.CAM16_to_XYZ` definition
n-dimensional support.
"""
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
surround = VIEWING_CONDITIONS_CAM16["Average"]
specification = XYZ_to_CAM16(XYZ, XYZ_w, L_A, Y_b, surround)
XYZ = CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround)
specification = CAM_Specification_CAM16(
*np.transpose(np.tile(tsplit(specification), (6, 1))).tolist())
XYZ = np.tile(XYZ, (6, 1))
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
XYZ,
decimal=7,
)
XYZ_w = np.tile(XYZ_w, (6, 1))
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
XYZ,
decimal=7,
)
specification = CAM_Specification_CAM16(
*tsplit(np.reshape(specification, (2, 3, 8))).tolist())
XYZ_w = np.reshape(XYZ_w, (2, 3, 3))
XYZ = np.reshape(XYZ, (2, 3, 3))
np.testing.assert_almost_equal(
CAM16_to_XYZ(specification, XYZ_w, L_A, Y_b, surround),
XYZ,
decimal=7,
)
def test_nan_CAM16_to_XYZ(self):
"""
Tests :func:`colour.appearance.cam16.CAM16_to_XYZ` definition
nan support.
"""
cases = [-1.0, 0.0, 1.0, -np.inf, np.inf, np.nan]
cases = set(permutations(cases * 3, r=3))
for case in cases:
J = case[0]
C = case[0]
h = case[0]
XYZ_w = np.array(case)
L_A = case[0]
Y_b = case[0]
surround = CAM16_InductionFactors(case[0], case[0], case[0])
CAM16_to_XYZ(CAM16_Specification(J, C, h), XYZ_w, L_A, Y_b,
surround)
def test_raise_exception_CAM16_to_XYZ(self):
"""
Tests :func:`colour.appearance.cam16.CAM16_to_XYZ` definition raised
exception.
"""
try:
CAM16_to_XYZ(
CAM16_Specification(
41.731207905126638,
None,
217.06795976739301,
),
np.array([95.05, 100.00, 108.88]),
318.31,
20.0,
CAM16_VIEWING_CONDITIONS['Average'],
)
except ValueError:
pass
def UCS_Li2017_to_XYZ(Jpapbp: ArrayLike, coefficients: ArrayLike,
**kwargs: Any) -> NDArray:
"""
Convert from one of the *Li et al. (2017)* *CAM16-LCD*, *CAM16-SCD*, or
*CAM16-UCS* colourspaces :math:`J'a'b'` array to *CIE XYZ* tristimulus
values.
Parameters
----------
Jpapbp
*Li et al. (2017)* *CAM16-LCD*, *CAM16-SCD*, or *CAM16-UCS*
colourspaces :math:`J'a'b'` array.
coefficients
Coefficients of one of the *Li et al. (2017)* *CAM16-LCD*, *CAM16-SCD*,
or *CAM16-UCS* colourspaces.
Other Parameters
----------------
kwargs
{:func:`colour.CAM16_to_XYZ`},
See the documentation of the previously listed definition. The default
viewing conditions are that of *IEC 61966-2-1:1999*, i.e. *sRGB* 64 Lux
ambient illumination, 80 :math:`cd/m^2`, adapting field luminance about
20% of a white object in the scene.
Returns
-------
:class:`numpy.ndarray`
*CIE XYZ* tristimulus values.
Warnings
--------
The ``XYZ_w`` parameter for :func:`colour.XYZ_to_CAM16` definition must be
given in the same domain-range scale than the ``XYZ`` parameter.
Notes
-----
+------------+------------------------+------------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+========================+==================+
| ``Jpapbp`` | ``Jp`` : [0, 100] | ``Jp`` : [0, 1] |
| | | |
| | ``ap`` : [-100, 100] | ``ap`` : [-1, 1] |
| | | |
| | ``bp`` : [-100, 100] | ``bp`` : [-1, 1] |
+------------+------------------------+------------------+
+------------+------------------------+------------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+============+========================+==================+
| ``XYZ`` | [0, 1] | [0, 1] |
+------------+------------------------+------------------+
Examples
--------
>>> import numpy as np
>>> Jpapbp = np.array([46.06586037, 41.07586491, 14.51025828])
>>> UCS_Li2017_to_XYZ(
... Jpapbp, COEFFICIENTS_UCS_LUO2006['CAM02-LCD'])
... # doctest: +ELLIPSIS
array([ 0.2065400..., 0.1219722..., 0.0513695...])
>>> from colour.appearance import CAM_KWARGS_CIECAM02_sRGB
>>> XYZ_w = CAM_KWARGS_CIECAM02_sRGB['XYZ_w']
>>> UCS_Li2017_to_XYZ(
... Jpapbp, COEFFICIENTS_UCS_LUO2006['CAM02-LCD'], XYZ_w=XYZ_w / 100)
... # doctest: +ELLIPSIS
array([ 0.2065400..., 0.1219722..., 0.0513695...])
"""
from colour.appearance import (
CAM_KWARGS_CIECAM02_sRGB,
CAM_Specification_CAM16,
CAM16_to_XYZ,
)
domain_range_reference = get_domain_range_scale() == "reference"
settings = CAM_KWARGS_CIECAM02_sRGB.copy()
settings.update(**kwargs)
XYZ_w = kwargs.get("XYZ_w")
if XYZ_w is not None and domain_range_reference:
settings["XYZ_w"] = XYZ_w * 100
J, M, h = tsplit(UCS_Li2017_to_JMh_CAM16(Jpapbp, coefficients))
specification = CAM_Specification_CAM16(J=J, M=M, h=h)
XYZ = CAM16_to_XYZ(specification, **settings)
if domain_range_reference:
XYZ /= 100
return XYZ
