def test_n_dimensional_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition n-dimensional arrays support.
"""
Y = 12.19722535 / 100
L_hdr = 31.996390226262736
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
Y = np.tile(Y, 6)
L_hdr = np.tile(L_hdr, 6)
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
Y = np.reshape(Y, (2, 3))
L_hdr = np.reshape(L_hdr, (2, 3))
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
Y = np.reshape(Y, (2, 3, 1))
L_hdr = np.reshape(L_hdr, (2, 3, 1))
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
def test_n_dimensional_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition n-dimensional arrays support.
"""
Y = 10.08 / 100
L = 23.10363383
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L, decimal=7)
Y = np.tile(Y, 6)
L = np.tile(L, 6)
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L, decimal=7)
Y = np.reshape(Y, (2, 3))
L = np.reshape(L, (2, 3))
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L, decimal=7)
Y = np.reshape(Y, (2, 3, 1))
L = np.reshape(L, (2, 3, 1))
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L, decimal=7)
def test_nan_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition nan support.
"""
lightness_Fairchild2010(
np.array([-1.0, 0.0, 1.0, -np.inf, np.inf, np.nan]))
def test_nan_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition nan support.
"""
lightness_Fairchild2010(
np.array([-1.0, 0.0, 1.0, -np.inf, np.inf, np.nan]))
def XYZ_to_hdr_CIELab(
XYZ,
illuminant=ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D50'],
Y_s=0.2,
Y_abs=100):
"""
Converts from *CIE XYZ* tristimulus values to *hdr-CIELAB* colourspace.
Parameters
----------
XYZ : array_like
*CIE XYZ* tristimulus values.
illuminant : array_like, optional
Reference *illuminant* *xy* chromaticity coordinates or *CIE xyY*
colourspace array.
Y_s : numeric or array_like
Relative luminance :math:`Y_s` of the surround in domain [0, 1].
Y_abs : numeric or array_like
Absolute luminance :math:`Y_{abs}` of the scene diffuse white in
:math:`cd/m^2`.
Returns
-------
ndarray
*hdr-CIELAB* colourspace array.
Notes
-----
- Conversion to polar coordinates to compute the *chroma* :math:`C_{hdr}`
and *hue* :math:`h_{hdr}` correlates can be safely performed with
:func:`colour.Lab_to_LCHab` definition.
- Conversion to cartesian coordinates from the *Lightness*
:math:`L_{hdr}`, *chroma* :math:`C_{hdr}` and *hue* :math:`h_{hdr}`
correlates can be safely performed with :func:`colour.LCHab_to_Lab`
definition.
- Input *CIE XYZ* tristimulus values are in domain [0, math:`\infty`].
- Input *illuminant* *xy* chromaticity coordinates or *CIE xyY*
colourspace array are in domain [0, :math:`\infty`].
Examples
--------
>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313])
>>> XYZ_to_hdr_CIELab(XYZ) # doctest: +ELLIPSIS
array([ 24.9020664..., -46.8312760..., -10.14274843])
"""
X, Y, Z = tsplit(XYZ)
X_n, Y_n, Z_n = tsplit(xyY_to_XYZ(xy_to_xyY(illuminant)))
e = exponent_hdr_CIELab(Y_s, Y_abs)
L_hdr = lightness_Fairchild2010(Y / Y_n, e)
a_hdr = 5 * (lightness_Fairchild2010(X / X_n, e) - L_hdr)
b_hdr = 2 * (L_hdr - lightness_Fairchild2010(Z / Z_n, e))
Lab_hdr = tstack((L_hdr, a_hdr, b_hdr))
return Lab_hdr
def test_domain_range_scale_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition domain and range scale support.
"""
L_hdr = lightness_Fairchild2010(12.19722535 / 100)
d_r = (('reference', 1, 1), (1, 1, 0.01), (100, 100, 1))
for scale, factor_a, factor_b in d_r:
with domain_range_scale(scale):
np.testing.assert_almost_equal(
lightness_Fairchild2010(12.19722535 / 100 * factor_a),
L_hdr * factor_b,
decimal=7)
def test_domain_range_scale_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition domain and range scale support.
"""
L_hdr = lightness_Fairchild2010(12.19722535 / 100)
d_r = (('reference', 1, 1), (1, 1, 0.01), (100, 100, 1))
for scale, factor_a, factor_b in d_r:
with domain_range_scale(scale):
np.testing.assert_almost_equal(
lightness_Fairchild2010(12.19722535 / 100 * factor_a),
L_hdr * factor_b,
decimal=7)
def test_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition.
"""
self.assertAlmostEqual(
lightness_Fairchild2010(12.19722535 / 100),
31.996390226262736,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(23.04276781 / 100),
60.203153682783302,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(6.15720079 / 100),
11.836517240976489,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(12.19722535 / 100, 2.75),
24.424283249379986,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(1008), 100.019986327374240, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(100800), 100.019999997090270, places=7)
def test_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition.
"""
self.assertAlmostEqual(
lightness_Fairchild2010(12.19722535 / 100),
31.996390226262736,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(23.04276781 / 100),
60.203153682783302,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(6.15720079 / 100),
11.836517240976489,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(12.19722535 / 100, 2.75),
24.424283249379986,
places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(1008), 100.019986327374240, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(100800), 100.019999997090270, places=7)
def test_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition.
"""
self.assertAlmostEqual(lightness_Fairchild2010(10.08 / 100),
24.90229027,
places=7)
self.assertAlmostEqual(lightness_Fairchild2010(56.76 / 100),
88.79756887,
places=7)
self.assertAlmostEqual(lightness_Fairchild2010(98.32 / 100),
95.61301852,
places=7)
self.assertAlmostEqual(lightness_Fairchild2010(10.08 / 100, 2.75),
16.06420271,
places=7)
self.assertAlmostEqual(lightness_Fairchild2010(1008),
100.019986327374240,
places=7)
self.assertAlmostEqual(lightness_Fairchild2010(100800),
100.019999997090270,
places=7)
def test_n_dimensional_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition n-dimensional arrays support.
"""
Y = 12.19722535 / 100
L_hdr = lightness_Fairchild2010(Y)
Y = np.tile(Y, 6)
L_hdr = np.tile(L_hdr, 6)
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
Y = np.reshape(Y, (2, 3))
L_hdr = np.reshape(L_hdr, (2, 3))
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
Y = np.reshape(Y, (2, 3, 1))
L_hdr = np.reshape(L_hdr, (2, 3, 1))
np.testing.assert_almost_equal(
lightness_Fairchild2010(Y), L_hdr, decimal=7)
def XYZ_to_hdr_IPT(XYZ, Y_s=0.2, Y_abs=100):
"""
Converts from *CIE XYZ* tristimulus values to *hdr-IPT* colourspace.
Parameters
----------
XYZ : array_like
*CIE XYZ* tristimulus values.
Y_s : numeric or array_like
Relative luminance :math:`Y_s` of the surround in domain [0, 1].
Y_abs : numeric or array_like
Absolute luminance :math:`Y_{abs}` of the scene diffuse white in
:math:`cd/m^2`.
Returns
-------
ndarray
*hdr-IPT* colourspace array.
Notes
-----
- Input *CIE XYZ* tristimulus values needs to be adapted for
*CIE Standard Illuminant D Series* *D65*.
Examples
--------
>>> XYZ = np.array([0.96907232, 1.00000000, 1.12179215])
>>> XYZ_to_hdr_IPT(XYZ) # doctest: +ELLIPSIS
array([ 94.6592917..., 0.3804177..., -0.2673118...])
"""
e = exponent_hdr_IPT(Y_s, Y_abs)[..., np.newaxis]
LMS = dot_vector(IPT_XYZ_TO_LMS_MATRIX, XYZ)
LMS_prime = np.sign(LMS) * np.abs(lightness_Fairchild2010(LMS, e))
IPT = dot_vector(IPT_LMS_TO_IPT_MATRIX, LMS_prime)
return IPT
def test_lightness_Fairchild2010(self):
"""
Tests :func:`colour.colorimetry.lightness.lightness_Fairchild2010`
definition.
"""
self.assertAlmostEqual(
lightness_Fairchild2010(10.08 / 100), 23.10363383, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(56.76 / 100), 90.51057574, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(98.32 / 100), 96.636221285, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(10.08 / 100, 2.75), 16.06420271, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(1008), 100.01999667, places=7)
self.assertAlmostEqual(
lightness_Fairchild2010(100800), 100.01999999, places=7)
