def domain(self, value):
"""
Setter for the **self.domain** property.
"""
if value is not None:
if np.asarray(value).dtype != object:
if not np.all(np.isfinite(value)):
runtime_warning(
'"{0}" new "domain" variable is not finite: {1}, '
'unpredictable results may occur!'.format(
self.name, value))
value = np.copy(value).astype(self.dtype)
if self._range is not None:
if value.size != self._range.size:
runtime_warning(
'"{0}" new "domain" and current "range" variables '
'have different size, "range" variable will be '
'resized to "domain" variable shape!'.format(
self.name))
self._range = np.resize(self._range, value.shape)
self._domain = value
self._create_function()
def domain(self, value):
"""
Setter for the **self.domain** property.
"""
if value is not None:
if not np.all(np.isfinite(value)):
runtime_warning(
'"{0}" new "domain" variable is not finite: {1}, '
'unpredictable results may occur!'.format(
self.name, value))
value = np.copy(value).astype(self.dtype)
if self._range is not None:
if value.size != self._range.size:
runtime_warning(
'"{0}" new "domain" and current "range" variables '
'have different size, "range" variable will be '
'resized to "domain" variable shape!'.format(
self.name))
self._range = np.resize(self._range, value.shape)
self._domain = value
self._create_function()
def illuminant(self): # pragma: no cover
# Docstrings are omitted for documentation purposes.
runtime_warning(
str(
ObjectRenamed('RGB_Colourspace.illuminant',
'RGB_Colourspace.whitepoint_name')))
return self.whitepoint_name
def encoding_cctf(self): # pragma: no cover
# Docstrings are omitted for documentation purposes.
runtime_warning(
str(
ObjectRenamed('RGB_Colourspace.encoding_cctf',
'RGB_Colourspace.cctf_encoding')))
return self.cctf_encoding
def illuminant(self, value):
# Docstrings are omitted for documentation purposes.
runtime_warning(
str(
Renamed('RGB_Colourspace.illuminant',
'RGB_Colourspace.whitepoint_name')))
self.whitepoint_name = value
def illuminant(self, value):
# Docstrings are omitted for documentation purposes.
runtime_warning(
str(
Renamed('RGB_Colourspace.illuminant',
'RGB_Colourspace.whitepoint_name')))
self.whitepoint_name = value
def training_data_sds_to_RGB(training_data, sensitivities, illuminant):
"""
Converts given training data to *RGB* tristimulus values using given
illuminant and given camera *RGB* spectral sensitivities.
Parameters
----------
training_data : MultiSpectralDistributions
Training data multi-spectral distributions.
sensitivities : RGB_CameraSensitivities
Camera *RGB* spectral sensitivities.
illuminant : SpectralDistribution
Illuminant spectral distribution.
Returns
-------
ndarray
Training data *RGB* tristimulus values.
Examples
--------
>>> path = os.path.join(
... RESOURCES_DIRECTORY_RAWTOACES,
... 'CANON_EOS_5DMark_II_RGB_Sensitivities.csv')
>>> sensitivities = sds_and_msds_to_msds(
... read_sds_from_csv_file(path).values())
>>> illuminant = normalise_illuminant(
... SDS_ILLUMINANTS['D55'], sensitivities)
>>> training_data = read_training_data_rawtoaces_v1()
>>> training_data_sds_to_RGB(training_data, sensitivities, illuminant)[:5]
... # doctest: +ELLIPSIS
array([[ 0.0207582..., 0.0196857..., 0.0213935...],
[ 0.0895775..., 0.0891922..., 0.0891091...],
[ 0.7810230..., 0.7801938..., 0.7764302...],
[ 0.1995 ..., 0.1995 ..., 0.1995 ...],
[ 0.5898478..., 0.5904015..., 0.5851076...]])
"""
shape = sensitivities.shape
if illuminant.shape != shape:
runtime_warning('Aligning "{0}" illuminant shape to "{1}".'.format(
illuminant.name, shape))
illuminant = illuminant.copy().align(shape)
if training_data.shape != shape:
runtime_warning('Aligning "{0}" training data shape to "{1}".'.format(
training_data.name, shape))
training_data = training_data.copy().align(shape)
RGB_w = white_balance_multipliers(sensitivities, illuminant)
RGB = np.dot(
np.transpose(
illuminant.values[..., np.newaxis] * training_data.values),
sensitivities.values)
RGB *= RGB_w
return RGB
def random_triplet_generator(size,
limits=np.array([[0, 1], [0, 1], [0, 1]]),
random_state=RANDOM_STATE):
"""
Returns a generator yielding random triplets.
Parameters
----------
size : int
Generator size.
limits : array_like, (3, 2)
Random values limits on each triplet axis.
random_state : RandomState
Mersenne Twister pseudo-random number generator.
Returns
-------
generator
Random triplets generator.
Notes
-----
- The test is assuming that :func:`np.random.RandomState` definition
will return the same sequence no matter which *OS* or *Python* version
is used. There is however no formal promise about the *prng* sequence
reproducibility of either *Python* or *Numpy* implementations, see
:cite:`Laurent2012a`.
Examples
--------
>>> from pprint import pprint
>>> prng = np.random.RandomState(4)
>>> random_triplet_generator(10, random_state=prng)
... # doctest: +ELLIPSIS
array([[ 0.9670298..., 0.7793829..., 0.4361466...],
[ 0.5472322..., 0.1976850..., 0.9489773...],
[ 0.9726843..., 0.8629932..., 0.7863059...],
[ 0.7148159..., 0.9834006..., 0.8662893...],
[ 0.6977288..., 0.1638422..., 0.1731654...],
[ 0.2160895..., 0.5973339..., 0.0749485...],
[ 0.9762744..., 0.0089861..., 0.6007427...],
[ 0.0062302..., 0.3865712..., 0.1679721...],
[ 0.2529823..., 0.0441600..., 0.7333801...],
[ 0.4347915..., 0.9566529..., 0.4084438...]])
"""
integer_size = DEFAULT_INT_DTYPE(size)
if integer_size != size:
runtime_warning(
'"size" has been cast to integer: {0}'.format(integer_size))
return tstack([
random_state.uniform(*limits[0], size=integer_size),
random_state.uniform(*limits[1], size=integer_size),
random_state.uniform(*limits[2], size=integer_size),
])
def random_triplet_generator(size,
limits=np.array([[0, 1], [0, 1], [0, 1]]),
random_state=RANDOM_STATE):
"""
Returns a generator yielding random triplets.
Parameters
----------
size : int
Generator size.
limits : array_like, (3, 2)
Random values limits on each triplet axis.
random_state : RandomState
Mersenne Twister pseudo-random number generator.
Returns
-------
generator
Random triplets generator.
Notes
-----
- The test is assuming that :func:`np.random.RandomState` definition
will return the same sequence no matter which *OS* or *Python* version
is used. There is however no formal promise about the *prng* sequence
reproducibility of either *Python* or *Numpy* implementations, see
:cite:`Laurent2012a`.
Examples
--------
>>> from pprint import pprint
>>> prng = np.random.RandomState(4)
>>> random_triplet_generator(10, random_state=prng)
... # doctest: +ELLIPSIS
array([[ 0.9670298..., 0.7793829..., 0.4361466...],
[ 0.5472322..., 0.1976850..., 0.9489773...],
[ 0.9726843..., 0.8629932..., 0.7863059...],
[ 0.7148159..., 0.9834006..., 0.8662893...],
[ 0.6977288..., 0.1638422..., 0.1731654...],
[ 0.2160895..., 0.5973339..., 0.0749485...],
[ 0.9762744..., 0.0089861..., 0.6007427...],
[ 0.0062302..., 0.3865712..., 0.1679721...],
[ 0.2529823..., 0.0441600..., 0.7333801...],
[ 0.4347915..., 0.9566529..., 0.4084438...]])
"""
integer_size = DEFAULT_INT_DTYPE(size)
if integer_size != size:
runtime_warning(
'"size" has been cast to integer: {0}'.format(integer_size))
return tstack([
random_state.uniform(*limits[0], size=integer_size),
random_state.uniform(*limits[1], size=integer_size),
random_state.uniform(*limits[2], size=integer_size),
])
def domain(self, value: ArrayLike):
"""Setter for the **self.domain** property."""
value = as_float_array(value, self.dtype)
if not np.all(np.isfinite(value)):
runtime_warning(
f'"{self.name}" new "domain" variable is not finite: {value}, '
f"unpredictable results may occur!"
)
if value.size != self._range.size:
self._range = np.resize(self._range, value.shape)
self._domain = value
self._create_function()
def normalise_illuminant(
illuminant: SpectralDistribution,
sensitivities: RGB_CameraSensitivities) -> SpectralDistribution:
"""
Normalise given illuminant with given camera *RGB* spectral sensitivities.
The multiplicative inverse scaling factor :math:`k` is computed by
multiplying the illuminant by the sensitivies channel with the maximum
value.
Parameters
----------
illuminant
Illuminant spectral distribution.
sensitivities
Camera *RGB* spectral sensitivities.
Returns
-------
:class:`colour.SpectralDistribution`
Normalised illuminant.
Examples
--------
>>> path = os.path.join(
... RESOURCES_DIRECTORY_RAWTOACES,
... 'CANON_EOS_5DMark_II_RGB_Sensitivities.csv')
>>> sensitivities = sds_and_msds_to_msds(
... read_sds_from_csv_file(path).values())
>>> illuminant = SDS_ILLUMINANTS['D55']
>>> np.sum(illuminant.values) # doctest: +ELLIPSIS
7276.1490000...
>>> np.sum(normalise_illuminant(illuminant, sensitivities).values)
... # doctest: +ELLIPSIS
3.4390373...
"""
shape = sensitivities.shape
if illuminant.shape != shape:
runtime_warning(
f'Aligning "{illuminant.name}" illuminant shape to "{shape}".')
illuminant = reshape_sd(illuminant, shape)
c_i = np.argmax(np.max(sensitivities.values, axis=0))
k = 1 / np.sum(illuminant.values * sensitivities.values[..., c_i])
return illuminant * k
def white_balance_multipliers(sensitivities: RGB_CameraSensitivities,
illuminant: SpectralDistribution) -> NDArray:
"""
Compute the *RGB* white balance multipliers for given camera *RGB*
spectral sensitivities and illuminant.
Parameters
----------
sensitivities
Camera *RGB* spectral sensitivities.
illuminant
Illuminant spectral distribution.
Returns
-------
:class:`numpy.ndarray`
*RGB* white balance multipliers.
References
----------
:cite:`Dyer2017`
Examples
--------
>>> path = os.path.join(
... RESOURCES_DIRECTORY_RAWTOACES,
... 'CANON_EOS_5DMark_II_RGB_Sensitivities.csv')
>>> sensitivities = sds_and_msds_to_msds(
... read_sds_from_csv_file(path).values())
>>> illuminant = SDS_ILLUMINANTS['D55']
>>> white_balance_multipliers(sensitivities, illuminant)
... # doctest: +ELLIPSIS
array([ 2.3414154..., 1. , 1.5163375...])
"""
shape = sensitivities.shape
if illuminant.shape != shape:
runtime_warning(
f'Aligning "{illuminant.name}" illuminant shape to "{shape}".')
illuminant = reshape_sd(illuminant, shape)
RGB_w = 1 / np.sum(
sensitivities.values * illuminant.values[..., np.newaxis], axis=0)
RGB_w *= 1 / np.min(RGB_w)
return RGB_w
def range(self, value: ArrayLike):
"""Setter for the **self.range** property."""
value = as_float_array(value, self.dtype)
if not np.all(np.isfinite(value)):
runtime_warning(
f'"{self.name}" new "range" variable is not finite: {value}, '
f"unpredictable results may occur!"
)
attest(
value.size == self._domain.size,
'"domain" and "range" variables must have same size!',
)
self._range = value
self._create_function()
def range(self, value):
"""
Setter for the **self.range** property.
"""
if value is not None:
if not np.all(np.isfinite(value)):
runtime_warning(
'"{0}" new "range" variable is not finite: {1}, '
'unpredictable results may occur!'.format(
self.name, value))
value = np.copy(value).astype(self.dtype)
if self._domain is not None:
assert value.size == self._domain.size, (
'"domain" and "range" variables must have same size!')
self._range = value
self._create_function()
def range(self, value):
"""
Setter for the **self.range** property.
"""
if value is not None:
if not np.all(np.isfinite(value)):
runtime_warning(
'"{0}" new "range" variable is not finite: {1}, '
'unpredictable results may occur!'.format(
self.name, value))
value = np.copy(value).astype(self.dtype)
if self._domain is not None:
assert value.size == self._domain.size, (
'"domain" and "range" variables must have same size!')
self._range = value
self._create_function()
def filter_passthrough(
mapping: Mapping,
filterers: Union[Any, str, Sequence[Union[Any, str]]],
anchors: Boolean = True,
allow_non_siblings: Boolean = True,
flags: Union[Integer, RegexFlag] = re.IGNORECASE,
) -> Dict:
"""
Return mapping objects matching given filterers while passing through
class instances whose type is one of the mapping element types.
This definition allows passing custom but compatible objects to the various
plotting definitions that by default expect the key from a dataset element.
For example, a typical call to :func:`colour.plotting.\
plot_multi_illuminant_sds` definition with a regex pattern automatically
anchored at boundaries by default is as follows:
>>> import colour
>>> colour.plotting.plot_multi_illuminant_sds(['A'])
... # doctest: +SKIP
Here, `'A'` is by default anchored at boundaries and transformed into
`'^A$'`. Note that because it is a regex pattern, special characters such
as parenthesis must be escaped: `'Adobe RGB (1998)'` must be written
`'Adobe RGB \\(1998\\)'` instead.
With the previous example, t is also possible to pass a custom spectral
distribution as follows:
>>> data = {
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360
... }
>>> colour.plotting.plot_multi_illuminant_sds(
... ['A', colour.SpectralDistribution(data)])
... # doctest: +SKIP
Similarly, a typical call to :func:`colour.plotting.\
plot_planckian_locus_in_chromaticity_diagram_CIE1931` definition is as follows:
>>> colour.plotting.plot_planckian_locus_in_chromaticity_diagram_CIE1931(
... ['A'])
... # doctest: +SKIP
But it is also possible to pass a custom whitepoint as follows:
>>> colour.plotting.plot_planckian_locus_in_chromaticity_diagram_CIE1931(
... ['A', {'Custom': np.array([1 / 3 + 0.05, 1 / 3 + 0.05])}])
... # doctest: +SKIP
Parameters
----------
mapping
Mapping to filter.
filterers
Filterer or object class instance (which is passed through directly if
its type is one of the mapping element types) or list
of filterers.
anchors
Whether to use Regex line anchors, i.e. *^* and *$* are added,
surrounding the filterers patterns.
allow_non_siblings
Whether to allow non-siblings to be also passed through.
flags
Regex flags.
Returns
-------
:class:`dict`
Filtered mapping.
"""
if is_string(filterers):
filterers = [filterers]
elif not isinstance(filterers, (list, tuple)):
filterers = [filterers]
string_filterers: List[str] = [
cast(str, filterer) for filterer in filterers if is_string(filterer)
]
object_filterers: List[Any] = [
filterer for filterer in filterers if is_sibling(filterer, mapping)
]
if allow_non_siblings:
non_siblings = [
filterer for filterer in filterers
if filterer not in string_filterers
and filterer not in object_filterers
]
if non_siblings:
runtime_warning(
f'Non-sibling elements are passed-through: "{non_siblings}"')
object_filterers.extend(non_siblings)
filtered_mapping = filter_mapping(mapping, string_filterers, anchors,
flags)
for filterer in object_filterers:
# TODO: Consider using "MutableMapping" here.
if isinstance(filterer, (dict, CaseInsensitiveMapping)):
for key, value in filterer.items():
filtered_mapping[key] = value
else:
try:
name = filterer.name
except AttributeError:
try:
name = filterer.__name__
except AttributeError:
name = str(id(filterer))
filtered_mapping[name] = filterer
return filtered_mapping
def spectral_primary_decomposition_Mallett2019(
colourspace,
cmfs=MSDS_CMFS_STANDARD_OBSERVER[
'CIE 1931 2 Degree Standard Observer'],
illuminant=SDS_ILLUMINANTS['D65'],
metric=np.linalg.norm,
metric_args=tuple(),
optimisation_kwargs=None):
"""
Performs the spectral primary decomposition as described in *Mallett and
Yuksel (2019)* for given *RGB* colourspace.
Parameters
----------
colourspace: RGB_Colourspace
*RGB* colourspace.
cmfs : XYZ_ColourMatchingFunctions, optional
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
metric : unicode, optional
Function to be minimised, i.e. the objective function.
``metric(basis, *metric_args) -> float``
where ``basis`` is three reflectances concatenated together, each
with a shape matching ``shape``.
metric_args : tuple, optional
Additional arguments passed to ``metric``.
optimisation_kwargs : dict_like, optional
Parameters for :func:`scipy.optimize.minimize` definition.
Returns
-------
MultiSpectralDistributions
Basis functions for given *RGB* colourspace.
References
----------
:cite:`Mallett2019`
Notes
-----
- In-addition to the *BT.709* primaries used by the *sRGB* colourspace,
:cite:`Mallett2019` tried *BT.2020*, *P3 D65*, *Adobe RGB 1998*,
*NTSC (1987)*, *Pal/Secam*, *ProPhoto RGB*,
and *Adobe Wide Gamut RGB* primaries, every one of which encompasses a
larger (albeit not-always-enveloping) set of *CIE L\\*a\\*b\\** colours
than BT.709. Of these, only *Pal/Secam* produces a feasible basis,
which is relatively unsurprising since it is very similar to *BT.709*,
whereas the others are significantly larger.
Examples
--------
>>> from colour.colorimetry import SpectralShape
>>> from colour.models import RGB_COLOURSPACE_PAL_SECAM
>>> from colour.utilities import numpy_print_options
>>> cmfs = (
... MSDS_CMFS_STANDARD_OBSERVER['CIE 1931 2 Degree Standard Observer'].
... copy().align(SpectralShape(360, 780, 10))
... )
>>> illuminant = SDS_ILLUMINANTS['D65'].copy().align(cmfs.shape)
>>> msds = spectral_primary_decomposition_Mallett2019(
... RGB_COLOURSPACE_PAL_SECAM, cmfs, illuminant, optimisation_kwargs={
... 'options': {'ftol': 1e-5}
... }
... )
>>> with numpy_print_options(suppress=True):
... # Doctests skip for Python 2.x compatibility.
... print(msds) # doctest: +SKIP
[[ 360. 0.3324728... 0.3332663... 0.3342608...]
[ 370. 0.3323307... 0.3327746... 0.3348946...]
[ 380. 0.3341115... 0.3323995... 0.3334889...]
[ 390. 0.3337570... 0.3298092... 0.3364336...]
[ 400. 0.3209352... 0.3218213... 0.3572433...]
[ 410. 0.2881025... 0.2837628... 0.4281346...]
[ 420. 0.1836749... 0.1838893... 0.6324357...]
[ 430. 0.0187212... 0.0529655... 0.9283132...]
[ 440. 0. ... 0. ... 1. ...]
[ 450. 0. ... 0. ... 1. ...]
[ 460. 0. ... 0. ... 1. ...]
[ 470. 0. ... 0.0509556... 0.9490443...]
[ 480. 0. ... 0.2933996... 0.7066003...]
[ 490. 0. ... 0.5001396... 0.4998603...]
[ 500. 0. ... 0.6734805... 0.3265195...]
[ 510. 0. ... 0.8555213... 0.1444786...]
[ 520. 0. ... 0.9999985... 0.0000014...]
[ 530. 0. ... 1. ... 0. ...]
[ 540. 0. ... 1. ... 0. ...]
[ 550. 0. ... 1. ... 0. ...]
[ 560. 0. ... 0.9924229... 0. ...]
[ 570. 0. ... 0.9913344... 0.0083032...]
[ 580. 0.0370289... 0.9145168... 0.0484542...]
[ 590. 0.7100075... 0.2898477... 0.0001446...]
[ 600. 1. ... 0. ... 0. ...]
[ 610. 1. ... 0. ... 0. ...]
[ 620. 1. ... 0. ... 0. ...]
[ 630. 1. ... 0. ... 0. ...]
[ 640. 0.9711347... 0.0137659... 0.0150993...]
[ 650. 0.7996619... 0.1119379... 0.0884001...]
[ 660. 0.6064640... 0.202815 ... 0.1907209...]
[ 670. 0.4662959... 0.2675037... 0.2662005...]
[ 680. 0.4010958... 0.2998989... 0.2990052...]
[ 690. 0.3617485... 0.3208921... 0.3173592...]
[ 700. 0.3496691... 0.3247855... 0.3255453...]
[ 710. 0.3433979... 0.3273540... 0.329248 ...]
[ 720. 0.3358860... 0.3345583... 0.3295556...]
[ 730. 0.3349498... 0.3314232... 0.3336269...]
[ 740. 0.3359954... 0.3340147... 0.3299897...]
[ 750. 0.3310392... 0.3327595... 0.3362012...]
[ 760. 0.3346883... 0.3314158... 0.3338957...]
[ 770. 0.3332167... 0.333371 ... 0.3334122...]
[ 780. 0.3319670... 0.3325476... 0.3354852...]]
"""
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
N = len(cmfs.shape)
R_to_XYZ = np.transpose(
np.expand_dims(illuminant.values, axis=1) * cmfs.values /
(np.sum(cmfs.values[:, 1] * illuminant.values)))
R_to_RGB = np.dot(colourspace.matrix_XYZ_to_RGB, R_to_XYZ)
basis_to_RGB = block_diag(R_to_RGB, R_to_RGB, R_to_RGB)
primaries = np.identity(3).reshape(9)
# Ensure the reflectances correspond to the correct RGB colours.
colour_match = LinearConstraint(basis_to_RGB, primaries, primaries)
# Ensure the reflectances are bounded by [0, 1].
energy_conservation = Bounds(np.zeros(3 * N), np.ones(3 * N))
# Ensure the sum of the three bases is bounded by [0, 1].
sum_matrix = np.transpose(np.tile(np.identity(N), (3, 1)))
sum_constraint = LinearConstraint(sum_matrix, np.zeros(N), np.ones(N))
optimisation_settings = {
'method': 'SLSQP',
'constraints': [colour_match, sum_constraint],
'bounds': energy_conservation,
'options': {
'ftol': 1e-10,
}
}
if optimisation_kwargs is not None:
optimisation_settings.update(optimisation_kwargs)
result = minimize(metric,
args=metric_args,
x0=np.zeros(3 * N),
**optimisation_settings)
basis_functions = np.transpose(result.x.reshape(3, N))
return MultiSpectralDistributions(
basis_functions,
cmfs.shape.range(),
name='Basis Functions - {0} - Mallett (2019)'.format(colourspace.name),
labels=('red', 'green', 'blue'))
def XYZ_to_sd_Meng2015(
XYZ,
cmfs=MSDS_CMFS_STANDARD_OBSERVER['CIE 1931 2 Degree Standard Observer']
.copy().align(SPECTRAL_SHAPE_MENG2015),
illuminant=SDS_ILLUMINANTS['D65'].copy().align(
SPECTRAL_SHAPE_MENG2015),
optimisation_kwargs=None,
**kwargs):
"""
Recovers the spectral distribution of given *CIE XYZ* tristimulus values
using *Meng et al. (2015)* method.
Parameters
----------
XYZ : array_like, (3,)
*CIE XYZ* tristimulus values to recover the spectral distribution from.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions. The wavelength
:math:`\\lambda_{i}` range interval of the colour matching functions
affects directly the time the computations take. The current default
interval of 5 is a good compromise between precision and time spent.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
optimisation_kwargs : dict_like, optional
Parameters for :func:`scipy.optimize.minimize` definition.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
SpectralDistribution
Recovered spectral distribution.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``XYZ`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
- The definition used to convert spectrum to *CIE XYZ* tristimulus
values is :func:`colour.colorimetry.spectral_to_XYZ_integration`
definition because it processes any measurement interval opposed to
:func:`colour.colorimetry.sd_to_XYZ_ASTME308` definition that
handles only measurement interval of 1, 5, 10 or 20nm.
References
----------
:cite:`Meng2015c`
Examples
--------
>>> from colour.utilities import numpy_print_options
>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
>>> cmfs = (
... MSDS_CMFS_STANDARD_OBSERVER['CIE 1931 2 Degree Standard Observer'].
... copy().align(SpectralShape(360, 780, 10))
... )
>>> illuminant = SDS_ILLUMINANTS['D65'].copy().align(cmfs.shape)
>>> sd = XYZ_to_sd_Meng2015(XYZ, cmfs, illuminant)
>>> with numpy_print_options(suppress=True):
... # Doctests skip for Python 2.x compatibility.
... sd # doctest: +SKIP
SpectralDistribution([[ 360. , 0.0765153...],
[ 370. , 0.0764771...],
[ 380. , 0.0764286...],
[ 390. , 0.0764329...],
[ 400. , 0.0765863...],
[ 410. , 0.0764339...],
[ 420. , 0.0757213...],
[ 430. , 0.0733091...],
[ 440. , 0.0676493...],
[ 450. , 0.0577616...],
[ 460. , 0.0440805...],
[ 470. , 0.0284802...],
[ 480. , 0.0138019...],
[ 490. , 0.0033557...],
[ 500. , 0. ...],
[ 510. , 0. ...],
[ 520. , 0. ...],
[ 530. , 0. ...],
[ 540. , 0.0055360...],
[ 550. , 0.0317335...],
[ 560. , 0.075457 ...],
[ 570. , 0.1314930...],
[ 580. , 0.1938219...],
[ 590. , 0.2559747...],
[ 600. , 0.3122869...],
[ 610. , 0.3584363...],
[ 620. , 0.3927112...],
[ 630. , 0.4158866...],
[ 640. , 0.4305832...],
[ 650. , 0.4391142...],
[ 660. , 0.4439484...],
[ 670. , 0.4464121...],
[ 680. , 0.4475718...],
[ 690. , 0.4481182...],
[ 700. , 0.4483734...],
[ 710. , 0.4484743...],
[ 720. , 0.4485753...],
[ 730. , 0.4486474...],
[ 740. , 0.4486629...],
[ 750. , 0.4486995...],
[ 760. , 0.4486925...],
[ 770. , 0.4486794...],
[ 780. , 0.4486982...]],
interpolator=SpragueInterpolator,
interpolator_kwargs={},
extrapolator=Extrapolator,
extrapolator_kwargs={...})
>>> sd_to_XYZ_integration(sd, cmfs, illuminant) / 100 # doctest: +ELLIPSIS
array([ 0.2065400..., 0.1219722..., 0.0513695...])
"""
optimisation_kwargs = handle_arguments_deprecation(
{
'ArgumentRenamed':
[['optimisation_parameters', 'optimisation_kwargs']],
}, **kwargs).get('optimisation_kwargs', optimisation_kwargs)
XYZ = to_domain_1(XYZ)
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
sd = sd_ones(cmfs.shape)
def objective_function(a):
"""
Objective function.
"""
return np.sum(np.diff(a)**2)
def constraint_function(a):
"""
Function defining the constraint.
"""
sd[:] = a
return sd_to_XYZ_integration(sd, cmfs=cmfs,
illuminant=illuminant) - XYZ
wavelengths = sd.wavelengths
bins = wavelengths.size
optimisation_settings = {
'method': 'SLSQP',
'constraints': {
'type': 'eq',
'fun': constraint_function
},
'bounds': np.tile(np.array([0, 1000]), (bins, 1)),
'options': {
'ftol': 1e-10,
},
}
if optimisation_kwargs is not None:
optimisation_settings.update(optimisation_kwargs)
result = minimize(objective_function, sd.values, **optimisation_settings)
if not result.success:
raise RuntimeError(
'Optimization failed for {0} after {1} iterations: "{2}".'.format(
XYZ, result.nit, result.message))
return SpectralDistribution(from_range_100(result.x * 100),
wavelengths,
name='{0} (XYZ) - Meng (2015)'.format(XYZ))
def filter_passthrough(mapping,
filterers,
anchors=True,
allow_non_siblings=True,
flags=re.IGNORECASE):
"""
Returns mapping objects matching given filterers while passing through
class instances whose type is one of the mapping element types.
This definition allows passing custom but compatible objects to the various
plotting definitions that by default expect the key from a dataset element.
For example, a typical call to :func:`colour.plotting.\
plot_multi_illuminant_sds` definition is as follows:
>>> import colour
>>> import colour.plotting
>>> colour.plotting.plot_multi_illuminant_sds(['A'])
... # doctest: +SKIP
But it is also possible to pass a custom spectral distribution as follows:
>>> data = {
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360
... }
>>> colour.plotting.plot_multi_illuminant_sds(
... ['A', colour.SpectralDistribution(data)])
... # doctest: +SKIP
Similarly, a typical call to :func:`colour.plotting.\
plot_planckian_locus_in_chromaticity_diagram_CIE1931` definition is as follows:
>>> colour.plotting.plot_planckian_locus_in_chromaticity_diagram_CIE1931(
... ['A'])
... # doctest: +SKIP
But it is also possible to pass a custom whitepoint as follows:
>>> colour.plotting.plot_planckian_locus_in_chromaticity_diagram_CIE1931(
... ['A', {'Custom': np.array([1 / 3 + 0.05, 1 / 3 + 0.05])}])
... # doctest: +SKIP
Parameters
----------
mapping : dict_like
Mapping to filter.
filterers : unicode or object or array_like
Filterer or object class instance (which is passed through directly if
its type is one of the mapping element types) or list
of filterers.
anchors : bool, optional
Whether to use Regex line anchors, i.e. *^* and *$* are added,
surrounding the filterers patterns.
allow_non_siblings : bool, optional
Whether to allow non-siblings to be also passed through.
flags : int, optional
Regex flags.
Returns
-------
dict_like
Filtered mapping.
"""
if is_string(filterers):
filterers = [filterers]
elif not isinstance(filterers, (list, tuple)):
filterers = [filterers]
string_filterers = [
filterer for filterer in filterers if is_string(filterer)
]
object_filterers = [
filterer for filterer in filterers if is_sibling(filterer, mapping)
]
if allow_non_siblings:
non_siblings = [
filterer for filterer in filterers
if filterer not in string_filterers and
filterer not in object_filterers
]
if non_siblings:
runtime_warning(
'Non-sibling elements are passed-through: "{0}"'.format(
non_siblings))
object_filterers.extend(non_siblings)
filtered_mapping = filter_mapping(mapping, string_filterers, anchors,
flags)
for filterer in object_filterers:
if isinstance(filterer, (dict, OrderedDict, CaseInsensitiveMapping)):
for key, value in filterer.items():
filtered_mapping[key] = value
else:
try:
name = filterer.name
except AttributeError:
try:
name = filterer.__name__
except AttributeError:
name = str(id(filterer))
filtered_mapping[name] = filterer
return filtered_mapping
def multi_sd_to_XYZ_integration(
msd,
shape,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(
STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'].shape)):
"""
Converts given multi-spectral distribution array :math:`msd` with given
spectral shape to *CIE XYZ* tristimulus values using given colour matching
functions and illuminant.
Parameters
----------
msa : array_like
Multi-spectral distribution array :math:`msd`, the wavelengths are
expected to be in the last axis, e.g. for a 512x384 multi-spectral
image with 77 bins, ``msd`` shape should be (384, 512, 77).
shape : SpectralShape, optional
Spectral shape of the multi-spectral distribution array :math:`msd`,
``cmfs`` and ``illuminant`` will be aligned with it.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
Returns
-------
array_like
*CIE XYZ* tristimulus values, for a 512x384 multi-spectral image with
77 bins, the output shape will be (384, 512, 3).
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`Wyszecki2000bf`
Examples
--------
>>> from colour import ILLUMINANTS_SDS
>>> msd = np.array([
... [
... [0.0137, 0.0913, 0.0152, 0.0281, 0.1918, 0.0430],
... [0.0159, 0.3145, 0.0842, 0.0907, 0.7103, 0.0437],
... [0.0096, 0.2582, 0.4139, 0.2228, 0.0041, 0.3744],
... [0.0111, 0.0709, 0.0220, 0.1249, 0.1817, 0.0020],
... [0.0179, 0.2971, 0.5630, 0.2375, 0.0024, 0.5819],
... [0.1057, 0.4620, 0.1918, 0.5625, 0.4209, 0.0027],
... ],
... [
... [0.0433, 0.2683, 0.2373, 0.0518, 0.0118, 0.0823],
... [0.0258, 0.0831, 0.0430, 0.3230, 0.2302, 0.0081],
... [0.0248, 0.1203, 0.0054, 0.0065, 0.1860, 0.3625],
... [0.0186, 0.1292, 0.0079, 0.4006, 0.9404, 0.3213],
... [0.0310, 0.1682, 0.3719, 0.0861, 0.0041, 0.7849],
... [0.0473, 0.3221, 0.2268, 0.3161, 0.1124, 0.0024],
... ],
... ])
>>> D65 = ILLUMINANTS_SDS['D65']
>>> multi_sd_to_XYZ(
... msd, SpectralShape(400, 700, 60), illuminant=D65)
... # doctest: +ELLIPSIS
array([[[ 7.1958378..., 3.8605390..., 10.1016398...],
[ 25.5738615..., 14.7200581..., 34.8440007...],
[ 17.5854414..., 28.5668344..., 30.1806687...],
[ 11.3271912..., 8.4598177..., 7.9015758...],
[ 19.6581831..., 35.5918480..., 35.1430220...],
[ 45.8212491..., 39.2600939..., 51.7907710...]],
<BLANKLINE>
[[ 8.8287837..., 13.3870357..., 30.5702050...],
[ 22.3324362..., 18.9560919..., 9.3952305...],
[ 6.6887212..., 2.5728891..., 13.2618778...],
[ 41.8166227..., 27.1191979..., 14.2627944...],
[ 9.2414098..., 20.2056200..., 20.1992502...],
[ 24.7830551..., 26.2221584..., 36.4430633...]]])
"""
msd = as_float_array(msd)
if cmfs.shape != shape:
runtime_warning('Aligning "{0}" cmfs shape to "{1}".'.format(
cmfs.name, shape))
cmfs = cmfs.copy().align(shape)
if illuminant.shape != shape:
runtime_warning('Aligning "{0}" illuminant shape to "{1}".'.format(
illuminant.name, shape))
illuminant = illuminant.copy().align(shape)
S = illuminant.values
x_bar, y_bar, z_bar = tsplit(cmfs.values)
dw = cmfs.shape.interval
k = 100 / (np.sum(y_bar * S) * dw)
X_p = msd * x_bar * S * dw
Y_p = msd * y_bar * S * dw
Z_p = msd * z_bar * S * dw
XYZ = k * np.sum(np.array([X_p, Y_p, Z_p]), axis=-1)
return from_range_100(np.rollaxis(XYZ, 0, msd.ndim))
def sd_to_XYZ_ASTME30815(
sd,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(ASTME30815_PRACTISE_SHAPE),
use_practice_range=True,
mi_5nm_omission_method=True,
mi_20nm_interpolation_method=True):
"""
Converts given spectral distribution to *CIE XYZ* tristimulus values using
given colour matching functions and illuminant according to practise
*ASTM E308-15* method.
Parameters
----------
sd : SpectralDistribution
Spectral distribution.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
use_practice_range : bool, optional
Practise *ASTM E308-15* working wavelengths range is [360, 780],
if *True* this argument will trim the colour matching functions
appropriately.
mi_5nm_omission_method : bool, optional
5 nm measurement intervals spectral distribution conversion to
tristimulus values will use a 5 nm version of the colour matching
functions instead of a table of tristimulus weighting factors.
mi_20nm_interpolation_method : bool, optional
20 nm measurement intervals spectral distribution conversion to
tristimulus values will use a dedicated interpolation method instead
of a table of tristimulus weighting factors.
Returns
-------
ndarray, (3,)
*CIE XYZ* tristimulus values.
Warning
-------
- The tables of tristimulus weighting factors are cached in
:attr:`colour.colorimetry.tristimulus.\
_TRISTIMULUS_WEIGHTING_FACTORS_CACHE` attribute. Their identifier key is
defined by the colour matching functions and illuminant names along
the current shape such as:
`CIE 1964 10 Degree Standard Observer, A, (360.0, 830.0, 10.0)`
Considering the above, one should be mindful that using similar colour
matching functions and illuminant names but with different spectral
data will lead to unexpected behaviour.
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`ASTMInternational2015b`
Examples
--------
>>> from colour import (
... CMFS, ILLUMINANTS_SDS, SpectralDistribution)
>>> cmfs = CMFS['CIE 1931 2 Degree Standard Observer']
>>> data = {
... 400: 0.0641,
... 420: 0.0645,
... 440: 0.0562,
... 460: 0.0537,
... 480: 0.0559,
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360,
... 620: 0.1511,
... 640: 0.1688,
... 660: 0.1996,
... 680: 0.2397,
... 700: 0.2852
... }
>>> sd = SpectralDistribution(data)
>>> illuminant = ILLUMINANTS_SDS['D65']
>>> sd_to_XYZ_ASTME30815(sd, cmfs, illuminant)
... # doctest: +ELLIPSIS
array([ 10.8399031..., 9.6840375..., 6.2164159...])
"""
if sd.shape.interval not in (1, 5, 10, 20):
raise ValueError(
'Tristimulus values conversion from spectral data according to '
'practise "ASTM E308-15" should be performed on spectral data '
'with measurement interval of 1, 5, 10 or 20nm!')
if use_practice_range:
cmfs = cmfs.copy().trim(ASTME30815_PRACTISE_SHAPE)
method = sd_to_XYZ_tristimulus_weighting_factors_ASTME30815
if sd.shape.interval == 1:
method = sd_to_XYZ_integration
elif sd.shape.interval == 5 and mi_5nm_omission_method:
if cmfs.shape.interval != 5:
cmfs = cmfs.copy().interpolate(SpectralShape(interval=5))
method = sd_to_XYZ_integration
elif sd.shape.interval == 20 and mi_20nm_interpolation_method:
sd = sd.copy()
if sd.shape.boundaries != cmfs.shape.boundaries:
runtime_warning(
'Trimming "{0}" spectral distribution shape to "{1}" '
'colour matching functions shape.'.format(
illuminant.name, cmfs.name))
sd.trim(cmfs.shape)
# Extrapolation of additional 20nm padding intervals.
sd.align(SpectralShape(sd.shape.start - 20, sd.shape.end + 20, 10))
for i in range(2):
sd[sd.wavelengths[i]] = (
3 * sd.values[i + 2] -
3 * sd.values[i + 4] + sd.values[i + 6]) # yapf: disable
i_e = len(sd.domain) - 1 - i
sd[sd.wavelengths[i_e]] = (sd.values[i_e - 6] -
3 * sd.values[i_e - 4] +
3 * sd.values[i_e - 2])
# Interpolating every odd numbered values.
# TODO: Investigate code vectorisation.
for i in range(3, len(sd.domain) - 3, 2):
sd[sd.wavelengths[i]] = (-0.0625 * sd.values[i - 3] +
0.5625 * sd.values[i - 1] +
0.5625 * sd.values[i + 1] -
0.0625 * sd.values[i + 3])
# Discarding the additional 20nm padding intervals.
sd.trim(SpectralShape(sd.shape.start + 20, sd.shape.end - 20, 10))
XYZ = method(sd, cmfs, illuminant)
return XYZ
def _uv_to_CCT_Ohno2013(
uv,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
start=CCT_MINIMAL,
end=CCT_MAXIMAL,
count=CCT_SAMPLES,
iterations=CCT_CALCULATION_ITERATIONS):
"""
Returns the correlated colour temperature :math:`T_{cp}` and
:math:`\\Delta_{uv}` from given *CIE UCS* colourspace *uv* chromaticity
coordinates, colour matching functions and temperature range using
*Ohno (2013)* method.
The iterations parameter defines the calculations precision: The higher its
value, the more planckian tables will be generated through cascade
expansion in order to converge to the exact solution.
Parameters
----------
uv : array_like
*CIE UCS* colourspace *uv* chromaticity coordinates.
cmfs : XYZ_ColourMatchingFunctions, optional
Standard observer colour matching functions.
start : numeric, optional
Temperature range start in kelvins.
end : numeric, optional
Temperature range end in kelvins.
count : int, optional
Temperatures count in the planckian tables.
iterations : int, optional
Number of planckian tables to generate.
Returns
-------
ndarray
Correlated colour temperature :math:`T_{cp}`, :math:`\\Delta_{uv}`.
"""
# Ensuring we do at least one iteration to initialise variables.
iterations = max(iterations, 1)
# Planckian table creation through cascade expansion.
for _i in range(iterations):
table = planckian_table(uv, cmfs, start, end, count)
index = planckian_table_minimal_distance_index(table)
if index == 0:
runtime_warning(
('Minimal distance index is on lowest planckian table bound, '
'unpredictable results may occur!'))
index += 1
elif index == len(table) - 1:
runtime_warning(
('Minimal distance index is on highest planckian table bound, '
'unpredictable results may occur!'))
index -= 1
start = table[index - 1].Ti
end = table[index + 1].Ti
_ux, vx = uv
Tuvdip, Tuvdi, Tuvdin = (table[index - 1], table[index], table[index + 1])
Tip, uip, vip, dip = Tuvdip.Ti, Tuvdip.ui, Tuvdip.vi, Tuvdip.di
Ti, di = Tuvdi.Ti, Tuvdi.di
Tin, uin, vin, din = Tuvdin.Ti, Tuvdin.ui, Tuvdin.vi, Tuvdin.di
# Triangular solution.
l = np.hypot(uin - uip, vin - vip) # noqa
x = (dip ** 2 - din ** 2 + l ** 2) / (2 * l)
T = Tip + (Tin - Tip) * (x / l)
vtx = vip + (vin - vip) * (x / l)
sign = 1 if vx - vtx >= 0 else -1
D_uv = (dip ** 2 - x ** 2) ** (1 / 2) * sign
# Parabolic solution.
if np.abs(D_uv) >= 0.002:
X = (Tin - Ti) * (Tip - Tin) * (Ti - Tip)
a = (Tip * (din - di) + Ti * (dip - din) + Tin * (di - dip)) * X ** -1
b = (-(Tip ** 2 * (din - di) + Ti ** 2 * (dip - din) + Tin ** 2 *
(di - dip)) * X ** -1)
c = (
-(dip * (Tin - Ti) * Ti * Tin + di *
(Tip - Tin) * Tip * Tin + din * (Ti - Tip) * Tip * Ti) * X ** -1)
T = -b / (2 * a)
D_uv = sign * (a * T ** 2 + b * T + c)
return np.array([T, D_uv])
def multi_sds_to_XYZ_integration(
msd,
shape,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(
STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'].
shape),
k=None):
"""
Converts given multi-spectral distribution array :math:`msd` with given
spectral shape to *CIE XYZ* tristimulus values using given colour matching
functions and illuminant.
Parameters
----------
msa : array_like
Multi-spectral distribution array :math:`msd`, the wavelengths are
expected to be in the last axis, e.g. for a 512x384 multi-spectral
image with 77 bins, ``msd`` shape should be (384, 512, 77).
shape : SpectralShape, optional
Spectral shape of the multi-spectral distribution array :math:`msd`,
``cmfs`` and ``illuminant`` will be aligned with it.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
k : numeric, optional
Normalisation constant :math:`k`. For reflecting or transmitting object
colours, :math:`k` is chosen so that :math:`Y = 100` for objects for
which the spectral reflectance factor :math:`R(\\lambda)` of the object
colour or the spectral transmittance factor :math:`\\tau(\\lambda)` of
the object is equal to unity for all wavelengths. For self-luminous
objects and illuminants, the constants :math:`k` is usually chosen on
the grounds of convenience. If, however, in the CIE 1931 standard
colorimetric system, the :math:`Y` value is required to be numerically
equal to the absolute value of a photometric quantity, the constant,
:math:`k`, must be put equal to the numerical value of :math:`K_m`, the
maximum spectral luminous efficacy (which is equal to
683 :math:`lm\\cdot W^{-1}`) and :math:`\\Phi_\\lambda(\\lambda)` must
be the spectral concentration of the radiometric quantity corresponding
to the photometric quantity required.
Returns
-------
array_like
*CIE XYZ* tristimulus values, for a 512x384 multi-spectral image with
77 bins, the output shape will be (384, 512, 3).
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`Wyszecki2000bf`
Examples
--------
>>> from colour import ILLUMINANTS_SDS
>>> msd = np.array([
... [
... [0.0137, 0.0913, 0.0152, 0.0281, 0.1918, 0.0430],
... [0.0159, 0.3145, 0.0842, 0.0907, 0.7103, 0.0437],
... [0.0096, 0.2582, 0.4139, 0.2228, 0.0041, 0.3744],
... [0.0111, 0.0709, 0.0220, 0.1249, 0.1817, 0.0020],
... [0.0179, 0.2971, 0.5630, 0.2375, 0.0024, 0.5819],
... [0.1057, 0.4620, 0.1918, 0.5625, 0.4209, 0.0027],
... ],
... [
... [0.0433, 0.2683, 0.2373, 0.0518, 0.0118, 0.0823],
... [0.0258, 0.0831, 0.0430, 0.3230, 0.2302, 0.0081],
... [0.0248, 0.1203, 0.0054, 0.0065, 0.1860, 0.3625],
... [0.0186, 0.1292, 0.0079, 0.4006, 0.9404, 0.3213],
... [0.0310, 0.1682, 0.3719, 0.0861, 0.0041, 0.7849],
... [0.0473, 0.3221, 0.2268, 0.3161, 0.1124, 0.0024],
... ],
... ])
>>> D65 = ILLUMINANTS_SDS['D65']
>>> multi_sds_to_XYZ(
... msd, SpectralShape(400, 700, 60), illuminant=D65)
... # doctest: +ELLIPSIS
array([[[ 7.1958378..., 3.8605390..., 10.1016398...],
[ 25.5738615..., 14.7200581..., 34.8440007...],
[ 17.5854414..., 28.5668344..., 30.1806687...],
[ 11.3271912..., 8.4598177..., 7.9015758...],
[ 19.6581831..., 35.5918480..., 35.1430220...],
[ 45.8212491..., 39.2600939..., 51.7907710...]],
<BLANKLINE>
[[ 8.8287837..., 13.3870357..., 30.5702050...],
[ 22.3324362..., 18.9560919..., 9.3952305...],
[ 6.6887212..., 2.5728891..., 13.2618778...],
[ 41.8166227..., 27.1191979..., 14.2627944...],
[ 9.2414098..., 20.2056200..., 20.1992502...],
[ 24.7830551..., 26.2221584..., 36.4430633...]]])
"""
msd = as_float_array(msd)
if cmfs.shape != shape:
runtime_warning('Aligning "{0}" cmfs shape to "{1}".'.format(
cmfs.name, shape))
cmfs = cmfs.copy().align(shape)
if illuminant.shape != shape:
runtime_warning('Aligning "{0}" illuminant shape to "{1}".'.format(
illuminant.name, shape))
illuminant = illuminant.copy().align(shape)
S = illuminant.values
x_bar, y_bar, z_bar = tsplit(cmfs.values)
dw = cmfs.shape.interval
k = 100 / (np.sum(y_bar * S) * dw) if k is None else k
X_p = msd * x_bar * S * dw
Y_p = msd * y_bar * S * dw
Z_p = msd * z_bar * S * dw
XYZ = k * np.sum(np.array([X_p, Y_p, Z_p]), axis=-1)
return from_range_100(np.rollaxis(XYZ, 0, msd.ndim))
def _uv_to_CCT_Ohno2013(
uv,
cmfs=MSDS_CMFS_STANDARD_OBSERVER['CIE 1931 2 Degree Standard Observer']
.copy().trim(SPECTRAL_SHAPE_DEFAULT),
start=CCT_MINIMAL,
end=CCT_MAXIMAL,
count=CCT_SAMPLES,
iterations=CCT_CALCULATION_ITERATIONS):
"""
Returns the correlated colour temperature :math:`T_{cp}` and
:math:`\\Delta_{uv}` from given *CIE UCS* colourspace *uv* chromaticity
coordinates, colour matching functions and temperature range using
*Ohno (2013)* method.
The iterations parameter defines the calculations precision: The higher its
value, the more planckian tables will be generated through cascade
expansion in order to converge to the exact solution.
Parameters
----------
uv : array_like
*CIE UCS* colourspace *uv* chromaticity coordinates.
cmfs : XYZ_ColourMatchingFunctions, optional
Standard observer colour matching functions.
start : numeric, optional
Temperature range start in kelvins.
end : numeric, optional
Temperature range end in kelvins.
count : int, optional
Temperatures count in the planckian tables.
iterations : int, optional
Number of planckian tables to generate.
Returns
-------
ndarray
Correlated colour temperature :math:`T_{cp}`, :math:`\\Delta_{uv}`.
"""
# Ensuring we do at least one iteration to initialise variables.
iterations = max(iterations, 1)
# Planckian table creation through cascade expansion.
for _i in range(iterations):
table = planckian_table(uv, cmfs, start, end, count)
index = planckian_table_minimal_distance_index(table)
if index == 0:
runtime_warning(
('Minimal distance index is on lowest planckian table bound, '
'unpredictable results may occur!'))
index += 1
elif index == len(table) - 1:
runtime_warning(
('Minimal distance index is on highest planckian table bound, '
'unpredictable results may occur!'))
index -= 1
start = table[index - 1].Ti
end = table[index + 1].Ti
_ux, vx = uv
Tuvdip, Tuvdi, Tuvdin = (table[index - 1], table[index], table[index + 1])
Tip, uip, vip, dip = Tuvdip.Ti, Tuvdip.ui, Tuvdip.vi, Tuvdip.di
Ti, di = Tuvdi.Ti, Tuvdi.di
Tin, uin, vin, din = Tuvdin.Ti, Tuvdin.ui, Tuvdin.vi, Tuvdin.di
# Triangular solution.
l = np.hypot(uin - uip, vin - vip) # noqa
x = (dip**2 - din**2 + l**2) / (2 * l)
T = Tip + (Tin - Tip) * (x / l)
vtx = vip + (vin - vip) * (x / l)
sign = 1 if vx - vtx >= 0 else -1
D_uv = (dip**2 - x**2)**(1 / 2) * sign
# Parabolic solution.
if np.abs(D_uv) >= 0.002:
X = (Tin - Ti) * (Tip - Tin) * (Ti - Tip)
a = (Tip * (din - di) + Ti * (dip - din) + Tin * (di - dip)) * X**-1
b = (-(Tip**2 * (din - di) + Ti**2 * (dip - din) + Tin**2 *
(di - dip)) * X**-1)
c = (-(dip * (Tin - Ti) * Ti * Tin + di *
(Tip - Tin) * Tip * Tin + din * (Ti - Tip) * Tip * Ti) * X**-1)
T = -b / (2 * a)
D_uv = sign * (a * T**2 + b * T + c)
return np.array([T, D_uv])
def filter_passthrough(mapping,
filterers,
anchors=True,
allow_non_siblings=True,
flags=re.IGNORECASE):
"""
Returns mapping objects matching given filterers while passing through
class instances whose type is one of the mapping element types.
This definition allows passing custom but compatible objects to the various
plotting definitions that by default expect the key from a dataset element.
For example, a typical call to :func:`colour.plotting.\
plot_multi_illuminant_sds` definition is as follows:
>>> import colour
>>> import colour.plotting
>>> colour.plotting.plot_multi_illuminant_sds(['A'])
... # doctest: +SKIP
But it is also possible to pass a custom spectral distribution as follows:
>>> data = {
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360
... }
>>> colour.plotting.plot_multi_illuminant_sds(
... ['A', colour.SpectralDistribution(data)])
... # doctest: +SKIP
Similarly, a typical call to :func:`colour.plotting.\
plot_planckian_locus_in_chromaticity_diagram_CIE1931` definition is as follows:
>>> colour.plotting.plot_planckian_locus_in_chromaticity_diagram_CIE1931(
... ['A'])
... # doctest: +SKIP
But it is also possible to pass a custom whitepoint as follows:
>>> colour.plotting.plot_planckian_locus_in_chromaticity_diagram_CIE1931(
... ['A', {'Custom': np.array([1 / 3 + 0.05, 1 / 3 + 0.05])}])
... # doctest: +SKIP
Parameters
----------
mapping : dict_like
Mapping to filter.
filterers : unicode or object or array_like
Filterer or object class instance (which is passed through directly if
its type is one of the mapping element types) or list
of filterers.
anchors : bool, optional
Whether to use Regex line anchors, i.e. *^* and *$* are added,
surrounding the filterers patterns.
allow_non_siblings : bool, optional
Whether to allow non-siblings to be also passed through.
flags : int, optional
Regex flags.
Returns
-------
dict_like
Filtered mapping.
"""
if is_string(filterers):
filterers = [filterers]
elif not isinstance(filterers, (list, tuple)):
filterers = [filterers]
string_filterers = [
filterer for filterer in filterers if is_string(filterer)
]
object_filterers = [
filterer for filterer in filterers if is_sibling(filterer, mapping)
]
if allow_non_siblings:
non_siblings = [
filterer for filterer in filterers
if filterer not in string_filterers
and filterer not in object_filterers
]
if non_siblings:
runtime_warning(
'Non-sibling elements are passed-through: "{0}"'.format(
non_siblings))
object_filterers.extend(non_siblings)
filtered_mapping = filter_mapping(mapping, string_filterers, anchors,
flags)
for filterer in object_filterers:
if isinstance(filterer, (dict, OrderedDict, CaseInsensitiveMapping)):
for key, value in filterer.items():
filtered_mapping[key] = value
else:
try:
name = filterer.name
except AttributeError:
try:
name = filterer.__name__
except AttributeError:
name = str(id(filterer))
filtered_mapping[name] = filterer
return filtered_mapping
def sd_to_XYZ_integration(
sd,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(
STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'].
shape),
k=None):
"""
Converts given spectral distribution to *CIE XYZ* tristimulus values
using given colour matching functions and illuminant according to classical
integration method.
Parameters
----------
sd : SpectralDistribution
Spectral distribution.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
k : numeric, optional
Normalisation constant :math:`k`. For reflecting or transmitting object
colours, :math:`k` is chosen so that :math:`Y = 100` for objects for
which the spectral reflectance factor :math:`R(\\lambda)` of the object
colour or the spectral transmittance factor :math:`\\tau(\\lambda)` of
the object is equal to unity for all wavelengths. For self-luminous
objects and illuminants, the constants :math:`k` is usually chosen on
the grounds of convenience. If, however, in the CIE 1931 standard
colorimetric system, the :math:`Y` value is required to be numerically
equal to the absolute value of a photometric quantity, the constant,
:math:`k`, must be put equal to the numerical value of :math:`K_m`, the
maximum spectral luminous efficacy (which is equal to
683 :math:`lm\\cdot W^{-1}`) and :math:`\\Phi_\\lambda(\\lambda)` must
be the spectral concentration of the radiometric quantity corresponding
to the photometric quantity required.
Returns
-------
ndarray, (3,)
*CIE XYZ* tristimulus values.
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`Wyszecki2000bf`
Examples
--------
>>> from colour import (
... CMFS, ILLUMINANTS_SDS, SpectralDistribution)
>>> cmfs = CMFS['CIE 1931 2 Degree Standard Observer']
>>> data = {
... 400: 0.0641,
... 420: 0.0645,
... 440: 0.0562,
... 460: 0.0537,
... 480: 0.0559,
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360,
... 620: 0.1511,
... 640: 0.1688,
... 660: 0.1996,
... 680: 0.2397,
... 700: 0.2852
... }
>>> sd = SpectralDistribution(data)
>>> illuminant = ILLUMINANTS_SDS['D65']
>>> sd_to_XYZ_integration(sd, cmfs, illuminant)
... # doctest: +ELLIPSIS
array([ 10.8401846..., 9.6837311..., 6.2120912...])
"""
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
if sd.shape != cmfs.shape:
runtime_warning('Aligning "{0}" spectral distribution shape to "{1}" '
'colour matching functions shape.'.format(
sd.name, cmfs.name))
sd = sd.copy().align(cmfs.shape)
S = illuminant.values
x_bar, y_bar, z_bar = tsplit(cmfs.values)
R = sd.values
dw = cmfs.shape.interval
k = 100 / (np.sum(y_bar * S) * dw) if k is None else k
X_p = R * x_bar * S * dw
Y_p = R * y_bar * S * dw
Z_p = R * z_bar * S * dw
XYZ = k * np.sum(np.array([X_p, Y_p, Z_p]), axis=-1)
return from_range_100(XYZ)
def plot_single_sd_colour_rendition_report_simple(
sd,
report_size=CONSTANT_REPORT_SIZE_SIMPLE,
report_row_height_ratios=CONSTANT_REPORT_ROW_HEIGHT_RATIOS_SIMPLE,
report_box_padding=None,
**kwargs):
"""
Generates the simple *ANSI/IES TM-30-18 Colour Rendition Report* for given
spectral distribution.
Parameters
----------
sd : SpectralDistribution or SpectralDistribution_IESTM2714
Spectral distribution of the emission source to generate the report
for.
report_size : array_like, optional
Report size, default to A4 paper size in inches.
report_row_height_ratios : array_like, optional
Report size row height ratios.
report_box_padding : array_like, optional
Report box padding, tries to define the padding around the figure and
in-between the axes.
Other Parameters
----------------
\\**kwargs : dict, optional
{:func:`colour.plotting.artist`, :func:`colour.plotting.render`},
Please refer to the documentation of the previously listed definitions.
Returns
-------
tuple
Current figure and axes.
Examples
--------
>>> from colour import SDS_ILLUMINANTS
>>> sd = SDS_ILLUMINANTS['FL2']
>>> plot_single_sd_colour_rendition_report_simple(sd)
... # doctest: +ELLIPSIS
(<Figure size ... with ... Axes>, <...AxesSubplot...>)
.. image:: ../_static/Plotting_\
Plot_Single_SD_Colour_Rendition_Report_Simple.png
:align: center
:alt: plot_single_sd_colour_rendition_report_simple
"""
if six.PY2:
runtime_warning(
'The "ANSI/IES TM-30-18 Colour Rendition Report" uses advanced '
'"Matplotlib" layout capabilities only available for Python 3!')
return render()
if report_box_padding is None:
report_box_padding = CONSTANT_REPORT_PADDING_SIMPLE
specification = colour_fidelity_index_ANSIIESTM3018(sd, True)
figure = plt.figure(figsize=report_size, constrained_layout=True)
settings = kwargs.copy()
settings['standalone'] = False
settings['tight_layout'] = False
gridspec_report = figure.add_gridspec(
3, 1, height_ratios=report_row_height_ratios)
# Title Row
gridspec_title = gridspec_report[0].subgridspec(1, 1)
axes_title = figure.add_subplot(gridspec_title[0])
_plot_report_header(axes_title)
# Main Figures Rows & Columns
gridspec_figures = gridspec_report[1].subgridspec(1, 1)
axes_vector_graphics = figure.add_subplot(gridspec_figures[0, 0])
plot_colour_vector_graphic(specification,
axes=axes_vector_graphics,
**settings)
gridspec_footer = gridspec_report[2].subgridspec(1, 1)
axes_footer = figure.add_subplot(gridspec_footer[0])
_plot_report_footer(axes_footer)
figure.set_constrained_layout_pads(**report_box_padding)
settings = kwargs.copy()
settings['tight_layout'] = False
return render(**settings)
def plot_single_sd_colour_rendition_report_full(
sd,
source=None,
date=None,
manufacturer=None,
model=None,
notes=None,
report_size=CONSTANT_REPORT_SIZE_FULL,
report_row_height_ratios=CONSTANT_REPORT_ROW_HEIGHT_RATIOS_FULL,
report_box_padding=None,
**kwargs):
"""
Generates the full *ANSI/IES TM-30-18 Colour Rendition Report* for given
spectral distribution.
Parameters
----------
sd : SpectralDistribution or SpectralDistribution_IESTM2714
Spectral distribution of the emission source to generate the report
for.
source : unicode, optional
Emission source name, defaults to
`colour.SpectralDistribution_IESTM2714.header.description` or
`colour.SpectralDistribution_IESTM2714.name` properties value.
date : unicode, optional
Emission source measurement date, defaults to
`colour.SpectralDistribution_IESTM2714.header.report_date` property
value.
manufacturer : unicode, optional
Emission source manufacturer, defaults to
`colour.SpectralDistribution_IESTM2714.header.manufacturer` property
value.
model : unicode, optional
Emission source model, defaults to
`colour.SpectralDistribution_IESTM2714.header.catalog_number` property
value.
notes : unicode, optional
Notes pertaining to the emission source, defaults to
`colour.SpectralDistribution_IESTM2714.header.comments` property
value.
report_size : array_like, optional
Report size, default to A4 paper size in inches.
report_row_height_ratios : array_like, optional
Report size row height ratios.
report_box_padding : array_like, optional
Report box padding, tries to define the padding around the figure and
in-between the axes.
Other Parameters
----------------
\\**kwargs : dict, optional
{:func:`colour.plotting.artist`, :func:`colour.plotting.render`},
Please refer to the documentation of the previously listed definitions.
Returns
-------
tuple
Current figure and axes.
Examples
--------
>>> from colour import SDS_ILLUMINANTS
>>> sd = SDS_ILLUMINANTS['FL2']
>>> plot_single_sd_colour_rendition_report_full(sd)
... # doctest: +ELLIPSIS
(<Figure size ... with ... Axes>, <...AxesSubplot...>)
.. image:: ../_static/Plotting_\
Plot_Single_SD_Colour_Rendition_Report_Full.png
:align: center
:alt: plot_single_sd_colour_rendition_report_full
"""
if six.PY2:
runtime_warning(
'The "ANSI/IES TM-30-18 Colour Rendition Report" uses advanced '
'"Matplotlib" layout capabilities only available for Python 3!')
return render()
if report_box_padding is None:
report_box_padding = CONSTANT_REPORT_PADDING_FULL
specification = colour_fidelity_index_ANSIIESTM3018(sd, True)
sd = (SpectralDistribution_IESTM2714(data=sd, name=sd.name)
if not isinstance(sd, SpectralDistribution_IESTM2714) else sd)
source = sd.header.description if source is None else source
source = sd.name if source is None else source
date = sd.header.report_date if date is None else date
date = _NOT_APPLICABLE_VALUE if date is None else date
manufacturer = (sd.header.manufacturer
if manufacturer is None else manufacturer)
manufacturer = (_NOT_APPLICABLE_VALUE
if manufacturer is None else manufacturer)
model = sd.header.catalog_number if model is None else model
model = _NOT_APPLICABLE_VALUE if model is None else model
notes = sd.header.comments if notes is None else notes
notes = _NOT_APPLICABLE_VALUE if notes is None else notes
figure = plt.figure(figsize=report_size, constrained_layout=True)
settings = kwargs.copy()
settings['standalone'] = False
settings['tight_layout'] = False
gridspec_report = figure.add_gridspec(
5, 1, height_ratios=report_row_height_ratios)
# Title Row
gridspec_title = gridspec_report[0].subgridspec(1, 1)
axes_title = figure.add_subplot(gridspec_title[0])
_plot_report_header(axes_title)
# Description Rows & Columns
gridspec_description = gridspec_report[1].subgridspec(1, 2)
# Source & Date Column
axes_source_date = figure.add_subplot(gridspec_description[0])
axes_source_date.set_axis_off()
axes_source_date.text(0.25,
2 / 3,
'Source: ',
ha='right',
va='center',
size='medium',
weight='bold')
axes_source_date.text(0.25, 2 / 3, source, va='center', size='medium')
axes_source_date.text(0.25,
1 / 3,
'Date: ',
ha='right',
va='center',
size='medium',
weight='bold')
axes_source_date.text(0.25, 1 / 3, date, va='center', size='medium')
# Manufacturer & Model Column
axes_manufacturer_model = figure.add_subplot(gridspec_description[1])
axes_manufacturer_model.set_axis_off()
axes_manufacturer_model.text(0.25,
2 / 3,
'Manufacturer: ',
ha='right',
va='center',
size='medium',
weight='bold')
axes_manufacturer_model.text(0.25,
2 / 3,
manufacturer,
va='center',
size='medium')
axes_manufacturer_model.text(0.25,
1 / 3,
'Model: ',
ha='right',
va='center',
size='medium',
weight='bold')
axes_manufacturer_model.text(0.25,
1 / 3,
model,
va='center',
size='medium')
# Main Figures Rows & Columns
gridspec_figures = gridspec_report[2].subgridspec(
4, 2, height_ratios=[1, 1, 1, 1.5])
axes_spectra = figure.add_subplot(gridspec_figures[0, 0])
plot_spectra_ANSIIESTM3018(specification, axes=axes_spectra, **settings)
axes_vector_graphics = figure.add_subplot(gridspec_figures[1:3, 0])
plot_colour_vector_graphic(specification,
axes=axes_vector_graphics,
**settings)
axes_chroma_shifts = figure.add_subplot(gridspec_figures[0, 1])
plot_local_chroma_shifts(specification,
axes=axes_chroma_shifts,
**settings)
axes_hue_shifts = figure.add_subplot(gridspec_figures[1, 1])
plot_local_hue_shifts(specification, axes=axes_hue_shifts, **settings)
axes_colour_fidelities = figure.add_subplot(gridspec_figures[2, 1])
plot_local_colour_fidelities(specification,
axes=axes_colour_fidelities,
x_ticker=True,
**settings)
# Colour Fidelity Indexes Row
axes_colour_fidelity_indexes = figure.add_subplot(gridspec_figures[3, :])
plot_colour_fidelity_indexes(specification,
axes=axes_colour_fidelity_indexes,
**settings)
# Notes & Chromaticities / CRI Row and Columns
gridspec_notes_chromaticities_CRI = gridspec_report[3].subgridspec(1, 2)
axes_notes = figure.add_subplot(gridspec_notes_chromaticities_CRI[0])
axes_notes.set_axis_off()
axes_notes.text(0.25,
1,
'Notes: ',
ha='right',
va='center',
size='medium',
weight='bold')
axes_notes.text(0.25, 1, notes, va='center', size='medium')
gridspec_chromaticities_CRI = gridspec_notes_chromaticities_CRI[
1].subgridspec(1, 2)
XYZ = sd_to_XYZ(specification.sd_test)
xy = XYZ_to_xy(XYZ)
Luv = XYZ_to_Luv(XYZ, xy)
uv_p = Luv_to_uv(Luv, xy)
gridspec_chromaticities = gridspec_chromaticities_CRI[0].subgridspec(1, 1)
axes_chromaticities = figure.add_subplot(gridspec_chromaticities[0])
axes_chromaticities.set_axis_off()
axes_chromaticities.text(0.5,
4 / 5,
'$x$ {:.4f}'.format(xy[0]),
ha='center',
va='center',
size='medium',
weight='bold')
axes_chromaticities.text(0.5,
3 / 5,
'$y$ {:.4f}'.format(xy[1]),
ha='center',
va='center',
size='medium',
weight='bold')
axes_chromaticities.text(0.5,
2 / 5,
'$u\'$ {:.4f}'.format(uv_p[0]),
ha='center',
va='center',
size='medium',
weight='bold')
axes_chromaticities.text(0.5,
1 / 5,
'$v\'$ {:.4f}'.format(uv_p[1]),
ha='center',
va='center',
size='medium',
weight='bold')
gridspec_CRI = gridspec_chromaticities_CRI[1].subgridspec(1, 1)
CRI_spec = colour_rendering_index(specification.sd_test,
additional_data=True)
axes_CRI = figure.add_subplot(gridspec_CRI[0])
axes_CRI.set_xticks([])
axes_CRI.set_yticks([])
axes_CRI.text(0.5,
4 / 5,
'CIE 13.31-1995',
ha='center',
va='center',
size='medium',
weight='bold')
axes_CRI.text(0.5,
3 / 5,
'(CRI)',
ha='center',
va='center',
size='medium',
weight='bold')
axes_CRI.text(0.5,
2 / 5,
'$R_a$ {:.0f}'.format(CRI_spec.Q_a),
ha='center',
va='center',
size='medium',
weight='bold')
axes_CRI.text(0.5,
1 / 5,
'$R_9$ {:.0f}'.format(CRI_spec.Q_as[8].Q_a),
ha='center',
va='center',
size='medium',
weight='bold')
gridspec_footer = gridspec_report[4].subgridspec(1, 1)
axes_footer = figure.add_subplot(gridspec_footer[0])
_plot_report_footer(axes_footer)
figure.set_constrained_layout_pads(**report_box_padding)
settings = kwargs.copy()
settings['tight_layout'] = False
return render(**settings)
warnings.warn('This is a fourth warning and it has not been filtered!')
filter_warnings(python_warnings=False)
warning('This is a fifth warning and it has been filtered!')
filter_warnings(False, python_warnings=False)
warning('This is a sixth warning and it has not been filtered!')
filter_warnings(False, python_warnings=False)
filter_warnings(colour_warnings=False, colour_runtime_warnings=True)
runtime_warning('This is a first runtime warning and it has been filtered!')
filter_warnings(colour_warnings=False, colour_usage_warnings=True)
usage_warning('This is a first usage warning and it has been filtered!')
print('\n')
message_box('Overall "Colour" Examples')
message_box('N-Dimensional Arrays Support')
XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
illuminant = np.array([0.31270, 0.32900])
message_box('Using 1d "array_like" parameter:\n' '\n{0}'.format(XYZ))
print(colour.XYZ_to_Lab(XYZ, illuminant=illuminant))
def sd_to_XYZ_tristimulus_weighting_factors_ASTME30815(
sd,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(ASTME30815_PRACTISE_SHAPE)):
"""
Converts given spectral distribution to *CIE XYZ* tristimulus values
using given colour matching functions and illuminant using a table of
tristimulus weighting factors according to practise *ASTM E308-15* method.
Parameters
----------
sd : SpectralDistribution
Spectral distribution.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
Returns
-------
ndarray, (3,)
*CIE XYZ* tristimulus values.
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`ASTMInternational2015b`
Examples
--------
>>> from colour import (
... CMFS, ILLUMINANTS_SDS, SpectralDistribution)
>>> cmfs = CMFS['CIE 1931 2 Degree Standard Observer']
>>> data = {
... 400: 0.0641,
... 420: 0.0645,
... 440: 0.0562,
... 460: 0.0537,
... 480: 0.0559,
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360,
... 620: 0.1511,
... 640: 0.1688,
... 660: 0.1996,
... 680: 0.2397,
... 700: 0.2852
... }
>>> sd = SpectralDistribution(data)
>>> illuminant = ILLUMINANTS_SDS['D65']
>>> sd_to_XYZ_tristimulus_weighting_factors_ASTME30815(
... sd, cmfs, illuminant) # doctest: +ELLIPSIS
array([ 10.8402899..., 9.6843539..., 6.2160858...])
"""
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
if sd.shape.boundaries != cmfs.shape.boundaries:
runtime_warning('Trimming "{0}" spectral distribution shape to "{1}" '
'colour matching functions shape.'.format(
illuminant.name, cmfs.name))
sd = sd.copy().trim(cmfs.shape)
W = tristimulus_weighting_factors_ASTME202211(
cmfs, illuminant,
SpectralShape(cmfs.shape.start, cmfs.shape.end, sd.shape.interval))
start_w = cmfs.shape.start
end_w = cmfs.shape.start + sd.shape.interval * (W.shape[0] - 1)
W = adjust_tristimulus_weighting_factors_ASTME30815(
W, SpectralShape(start_w, end_w, sd.shape.interval), sd.shape)
R = sd.values
XYZ = np.sum(W * R[..., np.newaxis], axis=0)
return from_range_100(XYZ)
def find_coefficients_Jakob2019(
XYZ,
cmfs=MSDS_CMFS_STANDARD_OBSERVER['CIE 1931 2 Degree Standard Observer']
.copy().align(SPECTRAL_SHAPE_JAKOB2019),
illuminant=SDS_ILLUMINANTS['D65'].copy().align(
SPECTRAL_SHAPE_JAKOB2019),
coefficients_0=zeros(3),
max_error=JND_CIE1976 / 100,
dimensionalise=True):
"""
Computes the coefficients for *Jakob and Hanika (2019)* reflectance
spectral model.
Parameters
----------
XYZ : array_like, (3,)
*CIE XYZ* tristimulus values to find the coefficients for.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution
Illuminant spectral distribution.
coefficients_0 : array_like, (3,), optional
Starting coefficients for the solver.
max_error : float, optional
Maximal acceptable error. Set higher to save computational time.
If *None*, the solver will keep going until it is very close to the
minimum. The default is ``ACCEPTABLE_DELTA_E``.
dimensionalise : bool, optional
If *True*, returned coefficients are dimensionful and will not work
correctly if fed back as ``coefficients_0``. The default is *True*.
Returns
-------
coefficients : ndarray, (3,)
Computed coefficients that best fit the given colour.
error : float
:math:`\\Delta E_{76}` between the target colour and the colour
corresponding to the computed coefficients.
References
----------
:cite:`Jakob2019`
Examples
--------
>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
>>> find_coefficients_Jakob2019(XYZ) # doctest: +ELLIPSIS
(array([ 1.3723791...e-04, -1.3514399...e-01, 3.0838973...e+01]), \
0.0141941...)
"""
shape = cmfs.shape
if illuminant.shape != shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
def optimize(target_o, coefficients_0_o):
"""
Minimises the error function using *L-BFGS-B* method.
"""
try:
result = minimize(
error_function,
coefficients_0_o, (target_o, cmfs, illuminant, max_error),
method='L-BFGS-B',
jac=True)
return result.x, result.fun
except StopMinimizationEarly as error:
return error.coefficients, error.error
xy_n = XYZ_to_xy(sd_to_XYZ(illuminant, cmfs))
XYZ_good = full(3, 0.5)
coefficients_good = zeros(3)
divisions = 3
while divisions < 10:
XYZ_r = XYZ_good
coefficient_r = coefficients_good
keep_divisions = False
coefficients_0 = coefficient_r
for i in range(1, divisions):
XYZ_i = (XYZ - XYZ_r) * i / (divisions - 1) + XYZ_r
Lab_i = XYZ_to_Lab(XYZ_i)
coefficients_0, error = optimize(Lab_i, coefficients_0)
if error > max_error:
break
else:
XYZ_good = XYZ_i
coefficients_good = coefficients_0
keep_divisions = True
else:
break
if not keep_divisions:
divisions += 2
target = XYZ_to_Lab(XYZ, xy_n)
coefficients, error = optimize(target, coefficients_0)
if dimensionalise:
coefficients = dimensionalise_coefficients(coefficients, shape)
return coefficients, error
def XYZ_to_sd_Meng2015(
XYZ,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'].
copy().align(DEFAULT_SPECTRAL_SHAPE_MENG_2015),
illuminant=sd_ones(DEFAULT_SPECTRAL_SHAPE_MENG_2015),
optimisation_parameters=None):
"""
Recovers the spectral distribution of given *CIE XYZ* tristimulus values
using *Meng et al. (2015)* method.
Parameters
----------
XYZ : array_like, (3,)
*CIE XYZ* tristimulus values to recover the spectral distribution from.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions. The wavelength
:math:`\\lambda_{i}` range interval of the colour matching functions
affects directly the time the computations take. The current default
interval of 5 is a good compromise between precision and time spent.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
optimisation_parameters : dict_like, optional
Parameters for :func:`scipy.optimize.minimize` definition.
Returns
-------
SpectralDistribution
Recovered spectral distribution.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``XYZ`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
- The definition used to convert spectrum to *CIE XYZ* tristimulus
values is :func:`colour.colorimetry.spectral_to_XYZ_integration`
definition because it processes any measurement interval opposed to
:func:`colour.colorimetry.sd_to_XYZ_ASTME308` definition that
handles only measurement interval of 1, 5, 10 or 20nm.
References
----------
:cite:`Meng2015c`
Examples
--------
>>> from colour.utilities import numpy_print_options
>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
>>> cmfs = (
... STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'].
... copy().align(SpectralShape(360, 780, 10))
... )
>>> sd = XYZ_to_sd_Meng2015(XYZ, cmfs)
>>> with numpy_print_options(suppress=True):
... # Doctests skip for Python 2.x compatibility.
... sd # doctest: +SKIP
SpectralDistribution([[ 360. , 0.0780114...],
[ 370. , 0.0780316...],
[ 380. , 0.0780471...],
[ 390. , 0.0780351...],
[ 400. , 0.0779702...],
[ 410. , 0.0778033...],
[ 420. , 0.0770958...],
[ 430. , 0.0748008...],
[ 440. , 0.0693230...],
[ 450. , 0.0601136...],
[ 460. , 0.0477407...],
[ 470. , 0.0334964...],
[ 480. , 0.0193352...],
[ 490. , 0.0074858...],
[ 500. , 0.0001225...],
[ 510. , 0. ...],
[ 520. , 0. ...],
[ 530. , 0. ...],
[ 540. , 0.0124896...],
[ 550. , 0.0389831...],
[ 560. , 0.0775105...],
[ 570. , 0.1247947...],
[ 580. , 0.1765339...],
[ 590. , 0.2281918...],
[ 600. , 0.2751347...],
[ 610. , 0.3140115...],
[ 620. , 0.3433561...],
[ 630. , 0.3635777...],
[ 640. , 0.3765428...],
[ 650. , 0.3841726...],
[ 660. , 0.3883633...],
[ 670. , 0.3905415...],
[ 680. , 0.3916742...],
[ 690. , 0.3922554...],
[ 700. , 0.3925427...],
[ 710. , 0.3926783...],
[ 720. , 0.3927330...],
[ 730. , 0.3927586...],
[ 740. , 0.3927548...],
[ 750. , 0.3927681...],
[ 760. , 0.3927813...],
[ 770. , 0.3927840...],
[ 780. , 0.3927536...]],
interpolator=SpragueInterpolator,
interpolator_args={},
extrapolator=Extrapolator,
extrapolator_args={...})
>>> sd_to_XYZ_integration(sd) / 100 # doctest: +ELLIPSIS
array([ 0.2065812..., 0.1219752..., 0.0514132...])
"""
XYZ = to_domain_1(XYZ)
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
sd = sd_ones(cmfs.shape)
def objective_function(a):
"""
Objective function.
"""
return np.sum(np.diff(a)**2)
def constraint_function(a):
"""
Function defining the constraint.
"""
sd[:] = a
return sd_to_XYZ_integration(sd, cmfs=cmfs,
illuminant=illuminant) - XYZ
wavelengths = sd.wavelengths
bins = wavelengths.size
optimisation_settings = {
'method': 'SLSQP',
'constraints': {
'type': 'eq',
'fun': constraint_function
},
'bounds': np.tile(np.array([0, 1000]), (bins, 1)),
'options': {
'ftol': 1e-10,
},
}
if optimisation_parameters is not None:
optimisation_settings.update(optimisation_parameters)
result = minimize(objective_function, sd.values, **optimisation_settings)
if not result.success:
raise RuntimeError(
'Optimization failed for {0} after {1} iterations: "{2}".'.format(
XYZ, result.nit, result.message))
return SpectralDistribution(from_range_100(result.x * 100),
wavelengths,
name='Meng (2015) - {0}'.format(XYZ))
def generate(self,
colourspace,
cmfs=MSDS_CMFS_STANDARD_OBSERVER[
'CIE 1931 2 Degree Standard Observer']
.copy().align(SPECTRAL_SHAPE_JAKOB2019),
illuminant=SDS_ILLUMINANTS['D65'].copy().align(
SPECTRAL_SHAPE_JAKOB2019),
size=64,
print_callable=print):
"""
Generates the lookup table data for given *RGB* colourspace, colour
matching functions, illuminant and given size.
Parameters
----------
colourspace: RGB_Colourspace
The *RGB* colourspace to create a lookup table for.
cmfs : XYZ_ColourMatchingFunctions, optional
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
size : int, optional
The resolution of the lookup table. Higher values will decrease
errors but at the cost of a much longer run time. The published
*\\*.coeff* files have a resolution of 64.
print_callable : callable, optional
Callable used to print progress and diagnostic information.
Examples
--------
>>> from colour.utilities import numpy_print_options
>>> from colour.models import RGB_COLOURSPACE_sRGB
>>> cmfs = MSDS_CMFS_STANDARD_OBSERVER[
... 'CIE 1931 2 Degree Standard Observer'].copy().align(
... SpectralShape(360, 780, 10))
>>> illuminant = SDS_ILLUMINANTS['D65'].copy().align(cmfs.shape)
>>> LUT = LUT3D_Jakob2019()
>>> print(LUT.interpolator)
None
>>> LUT.generate(RGB_COLOURSPACE_sRGB, cmfs, illuminant, 3)
======================================================================\
=========
* \
*
* "Jakob et al. (2018)" LUT Optimisation \
*
* \
*
======================================================================\
=========
<BLANKLINE>
Optimising 27 coefficients...
<BLANKLINE>
>>> print(LUT.interpolator)
... # doctest: +ELLIPSIS
<scipy.interpolate.interpolate.RegularGridInterpolator object at 0x...>
"""
shape = cmfs.shape
if illuminant.shape != shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
xy_n = XYZ_to_xy(sd_to_XYZ(illuminant, cmfs))
# It could be interesting to have different resolutions for lightness
# and chromaticity, but the current file format doesn't allow it.
lightness_steps = size
chroma_steps = size
self._lightness_scale = lightness_scale(lightness_steps)
self._coefficients = np.empty(
[3, chroma_steps, chroma_steps, lightness_steps, 3])
cube_indexes = np.ndindex(3, chroma_steps, chroma_steps)
total_coefficients = chroma_steps ** 2 * 3
# First, create a list of all the fully bright colours with the order
# matching cube_indexes.
samples = np.linspace(0, 1, chroma_steps)
ij = np.meshgrid(*[[1], samples, samples], indexing='ij')
ij = np.transpose(ij).reshape(-1, 3)
chromas = np.concatenate(
[ij, np.roll(ij, 1, axis=1),
np.roll(ij, 2, axis=1)])
message_box(
'"Jakob et al. (2018)" LUT Optimisation',
print_callable=print_callable)
print_callable(
'\nOptimising {0} coefficients...\n'.format(total_coefficients))
def optimize(ijkL, coefficients_0):
"""
Solves for a specific lightness and stores the result in the
appropriate cell.
"""
i, j, k, L = ijkL
RGB = self._lightness_scale[L] * chroma
XYZ = RGB_to_XYZ(RGB, colourspace.whitepoint, xy_n,
colourspace.matrix_RGB_to_XYZ)
coefficients, error = find_coefficients_Jakob2019(
XYZ, cmfs, illuminant, coefficients_0, dimensionalise=False)
self._coefficients[i, L, j, k, :] = dimensionalise_coefficients(
coefficients, shape)
return coefficients
with tqdm(total=total_coefficients) as progress:
for ijk, chroma in zip(cube_indexes, chromas):
progress.update()
# Starts from somewhere in the middle, similarly to how
# feedback works in "colour.recovery.\
# find_coefficients_Jakob2019" definition.
L_middle = lightness_steps // 3
coefficients_middle = optimize(
np.hstack([ijk, L_middle]), zeros(3))
# Goes down the lightness scale.
coefficients_0 = coefficients_middle
for L in reversed(range(0, L_middle)):
coefficients_0 = optimize(
np.hstack([ijk, L]), coefficients_0)
# Goes up the lightness scale.
coefficients_0 = coefficients_middle
for L in range(L_middle + 1, lightness_steps):
coefficients_0 = optimize(
np.hstack([ijk, L]), coefficients_0)
self._size = size
self._create_interpolator()
def sd_to_XYZ_integration(
sd,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(
STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'].shape)):
"""
Converts given spectral distribution to *CIE XYZ* tristimulus values
using given colour matching functions and illuminant according to classical
integration method.
Parameters
----------
sd : SpectralDistribution
Spectral distribution.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
Returns
-------
ndarray, (3,)
*CIE XYZ* tristimulus values.
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`Wyszecki2000bf`
Examples
--------
>>> from colour import (
... CMFS, ILLUMINANTS_SDS, SpectralDistribution)
>>> cmfs = CMFS['CIE 1931 2 Degree Standard Observer']
>>> data = {
... 400: 0.0641,
... 420: 0.0645,
... 440: 0.0562,
... 460: 0.0537,
... 480: 0.0559,
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360,
... 620: 0.1511,
... 640: 0.1688,
... 660: 0.1996,
... 680: 0.2397,
... 700: 0.2852
... }
>>> sd = SpectralDistribution(data)
>>> illuminant = ILLUMINANTS_SDS['D65']
>>> sd_to_XYZ_integration(sd, cmfs, illuminant)
... # doctest: +ELLIPSIS
array([ 10.8401846..., 9.6837311..., 6.2120912...])
"""
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
if sd.shape != cmfs.shape:
runtime_warning('Aligning "{0}" spectral distribution shape to "{1}" '
'colour matching functions shape.'.format(
sd.name, cmfs.name))
sd = sd.copy().align(cmfs.shape)
S = illuminant.values
x_bar, y_bar, z_bar = tsplit(cmfs.values)
R = sd.values
dw = cmfs.shape.interval
k = 100 / (np.sum(y_bar * S) * dw)
X_p = R * x_bar * S * dw
Y_p = R * y_bar * S * dw
Z_p = R * z_bar * S * dw
XYZ = k * np.sum(np.array([X_p, Y_p, Z_p]), axis=-1)
return from_range_100(XYZ)
def _uv_to_CCT_Ohno2013(
uv: ArrayLike,
cmfs: Optional[MultiSpectralDistributions] = None,
start: Floating = CCT_MINIMAL,
end: Floating = CCT_MAXIMAL,
count: Integer = CCT_SAMPLES,
iterations: Integer = CCT_CALCULATION_ITERATIONS,
) -> NDArray:
"""
Return the correlated colour temperature :math:`T_{cp}` and
:math:`\\Delta_{uv}` from given *CIE UCS* colourspace *uv* chromaticity
coordinates, colour matching functions and temperature range using
*Ohno (2013)* method.
The ``iterations`` parameter defines the calculations' precision: The
higher its value, the more planckian tables will be generated through
cascade expansion in order to converge to the exact solution.
Parameters
----------
uv
*CIE UCS* colourspace *uv* chromaticity coordinates.
cmfs
Standard observer colour matching functions, default to the
*CIE 1931 2 Degree Standard Observer*.
start
Temperature range start in kelvin degrees.
end
Temperature range end in kelvin degrees.
count
Temperatures count in the planckian tables.
iterations
Number of planckian tables to generate.
Returns
-------
:class:`numpy.ndarray`
Correlated colour temperature :math:`T_{cp}`, :math:`\\Delta_{uv}`.
"""
cmfs, _illuminant = handle_spectral_arguments(cmfs)
# Ensuring that we do at least one iteration to initialise the variables.
iterations = max(int(iterations), 1)
# Planckian table creation through cascade expansion.
for _i in range(iterations):
table = planckian_table(uv, cmfs, start, end, count)
index = planckian_table_minimal_distance_index(table)
if index == 0:
runtime_warning(
"Minimal distance index is on lowest planckian table bound, "
"unpredictable results may occur!")
index += 1
elif index == len(table) - 1:
runtime_warning(
"Minimal distance index is on highest planckian table bound, "
"unpredictable results may occur!")
index -= 1
start = table[index - 1].Ti
end = table[index + 1].Ti
_ux, vx = tsplit(uv)
Tuvdip, Tuvdi, Tuvdin = (table[index - 1], table[index], table[index + 1])
Tip, uip, vip, dip = Tuvdip.Ti, Tuvdip.ui, Tuvdip.vi, Tuvdip.di
Ti, di = Tuvdi.Ti, Tuvdi.di
Tin, uin, vin, din = Tuvdin.Ti, Tuvdin.ui, Tuvdin.vi, Tuvdin.di
# Triangular solution.
l = np.hypot(uin - uip, vin - vip) # noqa
x = (dip**2 - din**2 + l**2) / (2 * l)
T = Tip + (Tin - Tip) * (x / l)
vtx = vip + (vin - vip) * (x / l)
sign = 1 if vx - vtx >= 0 else -1
D_uv = (dip**2 - x**2)**(1 / 2) * sign
# Parabolic solution.
if np.abs(D_uv) >= 0.002:
X = (Tin - Ti) * (Tip - Tin) * (Ti - Tip)
a = (Tip * (din - di) + Ti * (dip - din) + Tin * (di - dip)) * X**-1
b = (-(Tip**2 * (din - di) + Ti**2 * (dip - din) + Tin**2 *
(di - dip)) * X**-1)
c = (-(dip * (Tin - Ti) * Ti * Tin + di *
(Tip - Tin) * Tip * Tin + din * (Ti - Tip) * Tip * Ti) * X**-1)
T = -b / (2 * a)
D_uv = sign * (a * T**2 + b * T + c)
return np.array([T, D_uv])
def sd_to_XYZ_tristimulus_weighting_factors_ASTME30815(
sd,
cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
illuminant=sd_ones(ASTME30815_PRACTISE_SHAPE),
k=None):
"""
Converts given spectral distribution to *CIE XYZ* tristimulus values
using given colour matching functions and illuminant using a table of
tristimulus weighting factors according to practise *ASTM E308-15* method.
Parameters
----------
sd : SpectralDistribution
Spectral distribution.
cmfs : XYZ_ColourMatchingFunctions
Standard observer colour matching functions.
illuminant : SpectralDistribution, optional
Illuminant spectral distribution.
k : numeric, optional
Normalisation constant :math:`k`. For reflecting or transmitting object
colours, :math:`k` is chosen so that :math:`Y = 100` for objects for
which the spectral reflectance factor :math:`R(\\lambda)` of the object
colour or the spectral transmittance factor :math:`\\tau(\\lambda)` of
the object is equal to unity for all wavelengths. For self-luminous
objects and illuminants, the constants :math:`k` is usually chosen on
the grounds of convenience. If, however, in the CIE 1931 standard
colorimetric system, the :math:`Y` value is required to be numerically
equal to the absolute value of a photometric quantity, the constant,
:math:`k`, must be put equal to the numerical value of :math:`K_m`, the
maximum spectral luminous efficacy (which is equal to
683 :math:`lm\\cdot W^{-1}`) and :math:`\\Phi_\\lambda(\\lambda)` must
be the spectral concentration of the radiometric quantity corresponding
to the photometric quantity required.
Returns
-------
ndarray, (3,)
*CIE XYZ* tristimulus values.
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``XYZ`` | [0, 100] | [0, 1] |
+-----------+-----------------------+---------------+
References
----------
:cite:`ASTMInternational2015b`
Examples
--------
>>> from colour import (
... CMFS, ILLUMINANTS_SDS, SpectralDistribution)
>>> cmfs = CMFS['CIE 1931 2 Degree Standard Observer']
>>> data = {
... 400: 0.0641,
... 420: 0.0645,
... 440: 0.0562,
... 460: 0.0537,
... 480: 0.0559,
... 500: 0.0651,
... 520: 0.0705,
... 540: 0.0772,
... 560: 0.0870,
... 580: 0.1128,
... 600: 0.1360,
... 620: 0.1511,
... 640: 0.1688,
... 660: 0.1996,
... 680: 0.2397,
... 700: 0.2852
... }
>>> sd = SpectralDistribution(data)
>>> illuminant = ILLUMINANTS_SDS['D65']
>>> sd_to_XYZ_tristimulus_weighting_factors_ASTME30815(
... sd, cmfs, illuminant) # doctest: +ELLIPSIS
array([ 10.8402899..., 9.6843539..., 6.2160858...])
"""
if illuminant.shape != cmfs.shape:
runtime_warning(
'Aligning "{0}" illuminant shape to "{1}" colour matching '
'functions shape.'.format(illuminant.name, cmfs.name))
illuminant = illuminant.copy().align(cmfs.shape)
if sd.shape.boundaries != cmfs.shape.boundaries:
runtime_warning('Trimming "{0}" spectral distribution shape to "{1}" '
'colour matching functions shape.'.format(
illuminant.name, cmfs.name))
sd = sd.copy().trim(cmfs.shape)
W = tristimulus_weighting_factors_ASTME202211(
cmfs, illuminant,
SpectralShape(cmfs.shape.start, cmfs.shape.end, sd.shape.interval), k)
start_w = cmfs.shape.start
end_w = cmfs.shape.start + sd.shape.interval * (W.shape[0] - 1)
W = adjust_tristimulus_weighting_factors_ASTME30815(
W, SpectralShape(start_w, end_w, sd.shape.interval), sd.shape)
R = sd.values
XYZ = np.sum(W * R[..., np.newaxis], axis=0)
return from_range_100(XYZ)