"""
RGB Colourspace and Transformations
===================================
Defines the :class:`colour.RGB_Colourspace` class for the *RGB* colourspaces
datasets from :mod:`colour.models.datasets.aces_rgb`, etc... and the following
*RGB* colourspace transformations or helper definitions:
- :func:`colour.XYZ_to_RGB`
- :func:`colour.RGB_to_XYZ`
- :func:`colour.matrix_RGB_to_RGB`
- :func:`colour.RGB_to_RGB`
References
----------
- :cite:`InternationalElectrotechnicalCommission1999a` : International
Electrotechnical Commission. (1999). IEC 61966-2-1:1999 - Multimedia
systems and equipment - Colour measurement and management - Part 2-1:
Colour management - Default RGB colour space - sRGB (p. 51).
https://webstore.iec.ch/publication/6169
- :cite:`Panasonic2014a` : Panasonic. (2014). VARICAM V-Log/V-Gamut (pp.
1-7).
http://pro-av.panasonic.net/en/varicam/common/pdf/VARICAM_V-Log_V-Gamut.pdf
"""
from __future__ import annotations
import numpy as np
from copy import deepcopy
from colour.adaptation import matrix_chromatic_adaptation_VonKries
from colour.algebra import matrix_dot, vector_dot
from colour.hints import (
Any,
ArrayLike,
Boolean,
Callable,
Literal,
NDArray,
Optional,
Union,
cast,
)
from colour.models import xy_to_XYZ, xy_to_xyY, xyY_to_XYZ
from colour.models.rgb import (
chromatically_adapted_primaries,
normalised_primary_matrix,
)
from colour.utilities import (
as_float_array,
attest,
domain_range_scale,
filter_kwargs,
from_range_1,
optional,
to_domain_1,
is_string,
)
__author__ = "Colour Developers"
__copyright__ = "Copyright 2013 Colour Developers"
__license__ = "New BSD License - https://opensource.org/licenses/BSD-3-Clause"
__maintainer__ = "Colour Developers"
__email__ = "colour-developers@colour-science.org"
__status__ = "Production"
__all__ = [
"RGB_Colourspace",
"XYZ_to_RGB",
"RGB_to_XYZ",
"matrix_RGB_to_RGB",
"RGB_to_RGB",
]
[docs]class RGB_Colourspace:
"""
Implement support for the *RGB* colourspaces datasets from
:mod:`colour.models.datasets.aces_rgb`, etc....
Colour science literature related to *RGB* colourspaces and encodings
defines their dataset using different degree of precision or rounding.
While instances where a whitepoint is being defined with a value
different than its canonical agreed one are rare, it is however very
common to have normalised primary matrices rounded at different
decimals. This can yield large discrepancies in computations.
Such an occurrence is the *V-Gamut* colourspace white paper, that defines
the *V-Gamut* to *ITU-R BT.709* conversion matrix as follows::
[[ 1.806576 -0.695697 -0.110879]
[-0.170090 1.305955 -0.135865]
[-0.025206 -0.154468 1.179674]]
Computing this matrix using *ITU-R BT.709* colourspace derived normalised
primary matrix yields::
[[ 1.8065736 -0.6956981 -0.1108786]
[-0.1700890 1.3059548 -0.1358648]
[-0.0252057 -0.1544678 1.1796737]]
The latter matrix is almost equals with the former, however performing the
same computation using *IEC 61966-2-1:1999* *sRGB* colourspace normalised
primary matrix introduces severe disparities::
[[ 1.8063853 -0.6956147 -0.1109453]
[-0.1699311 1.3058387 -0.1358616]
[-0.0251630 -0.1544899 1.1797117]]
In order to provide support for both literature defined dataset and
accurate computations enabling transformations without loss of precision,
the :class:`colour.RGB_Colourspace` class provides two sets of
transformation matrices:
- Instantiation transformation matrices
- Derived transformation matrices
Upon instantiation, the :class:`colour.RGB_Colourspace` class stores the
given ``matrix_RGB_to_XYZ`` and ``matrix_XYZ_to_RGB`` arguments and also
computes their derived counterpart using the ``primaries`` and
``whitepoint`` arguments.
Whether the initialisation or derived matrices are used in subsequent
computations is dependent on the
:attr:`colour.RGB_Colourspace.use_derived_matrix_RGB_to_XYZ` and
:attr:`colour.RGB_Colourspace.use_derived_matrix_XYZ_to_RGB` attribute
values.
Parameters
----------
name
*RGB* colourspace name.
primaries
*RGB* colourspace primaries.
whitepoint
*RGB* colourspace whitepoint.
whitepoint_name
*RGB* colourspace whitepoint name.
matrix_RGB_to_XYZ
Transformation matrix from colourspace to *CIE XYZ* tristimulus values.
matrix_XYZ_to_RGB
Transformation matrix from *CIE XYZ* tristimulus values to colourspace.
cctf_encoding
Encoding colour component transfer function (Encoding CCTF) /
opto-electronic transfer function (OETF) that maps estimated
tristimulus values in a scene to :math:`R'G'B'` video component signal
value.
cctf_decoding
Decoding colour component transfer function (Decoding CCTF) /
electro-optical transfer function (EOTF) that maps an
:math:`R'G'B'` video component signal value to tristimulus values at
the display.
use_derived_matrix_RGB_to_XYZ
Whether to use the instantiation time normalised primary matrix or to
use a computed derived normalised primary matrix.
use_derived_matrix_XYZ_to_RGB
Whether to use the instantiation time inverse normalised primary
matrix or to use a computed derived inverse normalised primary matrix.
Attributes
----------
- :attr:`~colour.RGB_Colourspace.name`
- :attr:`~colour.RGB_Colourspace.primaries`
- :attr:`~colour.RGB_Colourspace.whitepoint`
- :attr:`~colour.RGB_Colourspace.whitepoint_name`
- :attr:`~colour.RGB_Colourspace.matrix_RGB_to_XYZ`
- :attr:`~colour.RGB_Colourspace.matrix_XYZ_to_RGB`
- :attr:`~colour.RGB_Colourspace.cctf_encoding`
- :attr:`~colour.RGB_Colourspace.cctf_decoding`
- :attr:`~colour.RGB_Colourspace.use_derived_matrix_RGB_to_XYZ`
- :attr:`~colour.RGB_Colourspace.use_derived_matrix_XYZ_to_RGB`
Methods
-------
- :attr:`~colour.RGB_Colourspace.__init__`
- :attr:`~colour.RGB_Colourspace.__str__`
- :attr:`~colour.RGB_Colourspace.__repr__`
- :attr:`~colour.RGB_Colourspace.use_derived_transformation_matrices`
- :attr:`~colour.RGB_Colourspace.chromatically_adapt`
- :attr:`~colour.RGB_Colourspace.copy`
Notes
-----
- The normalised primary matrix defined by
:attr:`colour.RGB_Colourspace.matrix_RGB_to_XYZ` property is treated
as the prime matrix from which the inverse will be calculated as
required by the internal derivation mechanism. This behaviour has been
chosen in accordance with literature where commonly a *RGB* colourspace
is defined by its normalised primary matrix as it is directly computed
from the chosen primaries and whitepoint.
References
----------
:cite:`InternationalElectrotechnicalCommission1999a`,
:cite:`Panasonic2014a`
Examples
--------
>>> p = np.array([0.73470, 0.26530, 0.00000, 1.00000, 0.00010, -0.07700])
>>> whitepoint = np.array([0.32168, 0.33767])
>>> matrix_RGB_to_XYZ = np.identity(3)
>>> matrix_XYZ_to_RGB = np.identity(3)
>>> colourspace = RGB_Colourspace('RGB Colourspace', p, whitepoint, 'ACES',
... matrix_RGB_to_XYZ, matrix_XYZ_to_RGB)
>>> colourspace.matrix_RGB_to_XYZ
array([[ 1., 0., 0.],
[ 0., 1., 0.],
[ 0., 0., 1.]])
>>> colourspace.matrix_XYZ_to_RGB
array([[ 1., 0., 0.],
[ 0., 1., 0.],
[ 0., 0., 1.]])
>>> colourspace.use_derived_transformation_matrices(True)
>>> colourspace.matrix_RGB_to_XYZ # doctest: +ELLIPSIS
array([[ 9.5255239...e-01, 0.0000000...e+00, 9.3678631...e-05],
[ 3.4396645...e-01, 7.2816609...e-01, -7.2132546...e-02],
[ 0.0000000...e+00, 0.0000000...e+00, 1.0088251...e+00]])
>>> colourspace.matrix_XYZ_to_RGB # doctest: +ELLIPSIS
array([[ 1.0498110...e+00, 0.0000000...e+00, -9.7484540...e-05],
[ -4.9590302...e-01, 1.3733130...e+00, 9.8240036...e-02],
[ 0.0000000...e+00, 0.0000000...e+00, 9.9125201...e-01]])
>>> colourspace.use_derived_matrix_RGB_to_XYZ = False
>>> colourspace.matrix_RGB_to_XYZ
array([[ 1., 0., 0.],
[ 0., 1., 0.],
[ 0., 0., 1.]])
>>> colourspace.use_derived_matrix_XYZ_to_RGB = False
>>> colourspace.matrix_XYZ_to_RGB
array([[ 1., 0., 0.],
[ 0., 1., 0.],
[ 0., 0., 1.]])
"""
[docs] def __init__(
self,
name: str,
primaries: ArrayLike,
whitepoint: ArrayLike,
whitepoint_name: Optional[str] = None,
matrix_RGB_to_XYZ: Optional[ArrayLike] = None,
matrix_XYZ_to_RGB: Optional[ArrayLike] = None,
cctf_encoding: Optional[Callable] = None,
cctf_decoding: Optional[Callable] = None,
use_derived_matrix_RGB_to_XYZ: Boolean = False,
use_derived_matrix_XYZ_to_RGB: Boolean = False,
):
self._derived_matrix_RGB_to_XYZ: NDArray = np.array([])
self._derived_matrix_XYZ_to_RGB: NDArray = np.array([])
self._name: str = f"{self.__class__.__name__} ({id(self)})"
self.name = name
self._primaries: NDArray = np.array([])
self.primaries = primaries # type: ignore[assignment]
self._whitepoint: NDArray = np.array([])
self.whitepoint = whitepoint # type: ignore[assignment]
self._whitepoint_name: Optional[str] = None
self.whitepoint_name = whitepoint_name
self._matrix_RGB_to_XYZ: Optional[NDArray] = None
self.matrix_RGB_to_XYZ = matrix_RGB_to_XYZ # type: ignore[assignment]
self._matrix_XYZ_to_RGB: Optional[NDArray] = None
self.matrix_XYZ_to_RGB = matrix_XYZ_to_RGB # type: ignore[assignment]
self._cctf_encoding: Optional[Callable] = None
self.cctf_encoding = cctf_encoding
self._cctf_decoding: Optional[Callable] = None
self.cctf_decoding = cctf_decoding
self._use_derived_matrix_RGB_to_XYZ: Boolean = False
self.use_derived_matrix_RGB_to_XYZ = use_derived_matrix_RGB_to_XYZ
self._use_derived_matrix_XYZ_to_RGB: Boolean = False
self.use_derived_matrix_XYZ_to_RGB = use_derived_matrix_XYZ_to_RGB
@property
def name(self) -> str:
"""
Getter and setter property for the name.
Parameters
----------
value
Value to set the name with.
Returns
-------
:class:`str`
*RGB* colourspace name.
"""
return self._name
@name.setter
def name(self, value: str):
"""Setter for the **self.name** property."""
attest(
is_string(value),
f'"name" property: "{value}" type is not "str"!',
)
self._name = value
@property
def primaries(self) -> NDArray:
"""
Getter and setter property for the primaries.
Parameters
----------
value
Value to set the primaries with.
Returns
-------
:class:`numpy.ndarray`
*RGB* colourspace primaries.
"""
return self._primaries
@primaries.setter
def primaries(self, value: ArrayLike):
"""Setter for the **self.primaries** property."""
attest(
isinstance(value, (tuple, list, np.ndarray, np.matrix)),
f'"matrix_XYZ_to_RGB" property: "{value!r}" is not a "tuple", '
f'"list", "ndarray" or "matrix" instance!',
)
value = as_float_array(value)
value = np.reshape(value, (3, 2))
self._primaries = value
self._derive_transformation_matrices()
@property
def whitepoint(self) -> NDArray:
"""
Getter and setter property for the whitepoint.
Parameters
----------
value
Value to set the whitepoint with.
Returns
-------
:class:`numpy.ndarray`
*RGB* colourspace whitepoint.
"""
return self._whitepoint
@whitepoint.setter
def whitepoint(self, value: ArrayLike):
"""Setter for the **self.whitepoint** property."""
attest(
isinstance(value, (tuple, list, np.ndarray, np.matrix)),
f'"matrix_XYZ_to_RGB" property: "{value!r}" is not a "tuple", '
f'"list", "ndarray" or "matrix" instance!',
)
value = as_float_array(value)
self._whitepoint = value
self._derive_transformation_matrices()
@property
def whitepoint_name(self) -> Optional[str]:
"""
Getter and setter property for the whitepoint_name.
Parameters
----------
value
Value to set the whitepoint_name with.
Returns
-------
:py:data:`None` or :class:`str`
*RGB* colourspace whitepoint name.
"""
return self._whitepoint_name
@whitepoint_name.setter
def whitepoint_name(self, value: Optional[str]):
"""Setter for the **self.whitepoint_name** property."""
if value is not None:
attest(
is_string(value),
f'"whitepoint_name" property: "{value}" type is not "str"!',
)
self._whitepoint_name = value
@property
def matrix_RGB_to_XYZ(self) -> NDArray:
"""
Getter and setter property for the transformation matrix from
colourspace to *CIE XYZ* tristimulus values.
Parameters
----------
value
Transformation matrix from colourspace to *CIE XYZ* tristimulus
values.
Returns
-------
:class:`numpy.ndarray`
Transformation matrix from colourspace to *CIE XYZ* tristimulus
values.
"""
if (
self._matrix_RGB_to_XYZ is None
or self._use_derived_matrix_RGB_to_XYZ
):
return self._derived_matrix_RGB_to_XYZ
else:
return self._matrix_RGB_to_XYZ
@matrix_RGB_to_XYZ.setter
def matrix_RGB_to_XYZ(self, value: Optional[ArrayLike]):
"""Setter for the **self.matrix_RGB_to_XYZ** property."""
if value is not None:
attest(
isinstance(value, (tuple, list, np.ndarray, np.matrix)),
f'"matrix_RGB_to_XYZ" property: "{value!r}" is not a "tuple", '
f'"list", "ndarray" or "matrix" instance!',
)
value = as_float_array(value)
self._matrix_RGB_to_XYZ = value
@property
def matrix_XYZ_to_RGB(self) -> NDArray:
"""
Getter and setter property for the transformation matrix from *CIE XYZ*
tristimulus values to colourspace.
Parameters
----------
value
Transformation matrix from *CIE XYZ* tristimulus values to
colourspace.
Returns
-------
:class:`numpy.ndarray`
Transformation matrix from *CIE XYZ* tristimulus values to
colourspace.
"""
if (
self._matrix_XYZ_to_RGB is None
or self._use_derived_matrix_XYZ_to_RGB
):
return self._derived_matrix_XYZ_to_RGB
else:
return self._matrix_XYZ_to_RGB
@matrix_XYZ_to_RGB.setter
def matrix_XYZ_to_RGB(self, value: Optional[ArrayLike]):
"""Setter for the **self.matrix_XYZ_to_RGB** property."""
if value is not None:
attest(
isinstance(value, (tuple, list, np.ndarray, np.matrix)),
f'"matrix_XYZ_to_RGB" property: "{value!r}" is not a "tuple", '
f'"list", "ndarray" or "matrix" instance!',
)
value = as_float_array(value)
self._matrix_XYZ_to_RGB = value
@property
def cctf_encoding(self) -> Optional[Callable]:
"""
Getter and setter property for the encoding colour component transfer
function (Encoding CCTF) / opto-electronic transfer function
(OETF).
Parameters
----------
value
Encoding colour component transfer function (Encoding CCTF) /
opto-electronic transfer function (OETF).
Returns
-------
:py:data:`None` or Callable
Encoding colour component transfer function (Encoding CCTF) /
opto-electronic transfer function (OETF).
"""
return self._cctf_encoding
@cctf_encoding.setter
def cctf_encoding(self, value: Optional[Callable]):
"""Setter for the **self.cctf_encoding** property."""
if value is not None:
attest(
hasattr(value, "__call__"),
f'"cctf_encoding" property: "{value}" is not callable!',
)
self._cctf_encoding = value
@property
def cctf_decoding(self) -> Optional[Callable]:
"""
Getter and setter property for the decoding colour component transfer
function (Decoding CCTF) / electro-optical transfer function
(EOTF).
Parameters
----------
value
Decoding colour component transfer function (Decoding CCTF) /
electro-optical transfer function (EOTF).
Returns
-------
:py:data:`None` or Callable
Decoding colour component transfer function (Decoding CCTF) /
electro-optical transfer function (EOTF).
"""
return self._cctf_decoding
@cctf_decoding.setter
def cctf_decoding(self, value: Optional[Callable]):
"""Setter for the **self.cctf_decoding** property."""
if value is not None:
attest(
hasattr(value, "__call__"),
f'"cctf_decoding" property: "{value}" is not callable!',
)
self._cctf_decoding = value
@property
def use_derived_matrix_RGB_to_XYZ(self) -> Boolean:
"""
Getter and setter property for whether to use the instantiation time
normalised primary matrix or to use a computed derived normalised
primary matrix.
Parameters
----------
value
Whether to use the instantiation time normalised primary matrix or
to use a computed derived normalised primary matrix.
Returns
-------
:class:`bool`
Whether to use the instantiation time normalised primary matrix or
to use a computed derived normalised primary matrix.
"""
return self._use_derived_matrix_RGB_to_XYZ
@use_derived_matrix_RGB_to_XYZ.setter
def use_derived_matrix_RGB_to_XYZ(self, value: Boolean):
"""Setter for the **self.use_derived_matrix_RGB_to_XYZ** property."""
attest(
isinstance(value, (bool, np.bool_)),
f'"use_derived_matrix_RGB_to_XYZ" property: "{value}" is not a '
f'"bool"!',
)
self._use_derived_matrix_RGB_to_XYZ = value
@property
def use_derived_matrix_XYZ_to_RGB(self) -> Boolean:
"""
Getter and setter property for Whether to use the instantiation time
inverse normalised primary matrix or to use a computed derived inverse
normalised primary matrix.
Parameters
----------
value
Whether to use the instantiation time inverse normalised primary
matrix or to use a computed derived inverse normalised primary
matrix.
Returns
-------
:class:`bool`
Whether to use the instantiation time inverse normalised primary
matrix or to use a computed derived inverse normalised primary
matrix.
"""
return self._use_derived_matrix_XYZ_to_RGB
@use_derived_matrix_XYZ_to_RGB.setter
def use_derived_matrix_XYZ_to_RGB(self, value: Boolean):
"""Setter for the **self.use_derived_matrix_XYZ_to_RGB** property."""
attest(
isinstance(value, (bool, np.bool_)),
f'"use_derived_matrix_XYZ_to_RGB" property: "{value}" is not a '
f'"bool"!',
)
self._use_derived_matrix_XYZ_to_RGB = value
[docs] def __str__(self) -> str:
"""
Return a formatted string representation of the *RGB* colourspace.
Returns
-------
:class:`str`
Formatted string representation.
Examples
--------
>>> p = np.array(
... [0.73470, 0.26530, 0.00000, 1.00000, 0.00010, -0.07700])
>>> whitepoint = np.array([0.32168, 0.33767])
>>> matrix_RGB_to_XYZ = np.identity(3)
>>> matrix_XYZ_to_RGB = np.identity(3)
>>> cctf_encoding = lambda x: x
>>> cctf_decoding = lambda x: x
>>> print(RGB_Colourspace('RGB Colourspace', p, whitepoint, 'ACES',
... matrix_RGB_to_XYZ, matrix_XYZ_to_RGB,
... cctf_encoding, cctf_decoding))
... # doctest: +ELLIPSIS
RGB Colourspace
---------------
<BLANKLINE>
Primaries : [[ 7.34700000e-01 2.65300000e-01]
[ 0.00000000e+00 1.00000000e+00]
[ 1.00000000e-04 -7.70000000e-02]]
Whitepoint : [ 0.32168 0.33767]
Whitepoint Name : ACES
Encoding CCTF : <function <lambda> at 0x...>
Decoding CCTF : <function <lambda> at 0x...>
NPM : [[ 1. 0. 0.]
[ 0. 1. 0.]
[ 0. 0. 1.]]
NPM -1 : [[ 1. 0. 0.]
[ 0. 1. 0.]
[ 0. 0. 1.]]
Derived NPM : \
[[ 9.5255239...e-01 0.0000000...e+00 9.3678631...e-05]
\
[ 3.4396645...e-01 7.2816609...e-01 -7.2132546...e-02]
\
[ 0.0000000...e+00 0.0000000...e+00 1.0088251...e+00]]
Derived NPM -1 : \
[[ 1.0498110...e+00 0.0000000...e+00 -9.7484540...e-05]
\
[ -4.9590302...e-01 1.3733130...e+00 9.8240036...e-02]
\
[ 0.0000000...e+00 0.0000000...e+00 9.9125201...e-01]]
Use Derived NPM : False
Use Derived NPM -1 : False
"""
def _indent_array(a: Optional[NDArray]) -> str:
"""Indent given array string representation."""
return str(a).replace(" [", " " * 22 + "[")
return (
f"{self.name}\n"
f'{"-" * len(self.name)}\n\n'
f"Primaries : {_indent_array(self.primaries)}\n"
f"Whitepoint : {self.whitepoint}\n"
f"Whitepoint Name : {self.whitepoint_name}\n"
f"Encoding CCTF : {self.cctf_encoding}\n"
f"Decoding CCTF : {self.cctf_decoding}\n"
f"NPM : {_indent_array(self._matrix_RGB_to_XYZ)}\n"
f"NPM -1 : {_indent_array(self._matrix_XYZ_to_RGB)}\n"
f"Derived NPM : {_indent_array(self._derived_matrix_RGB_to_XYZ)}\n"
f"Derived NPM -1 : {_indent_array(self._derived_matrix_XYZ_to_RGB)}\n"
f"Use Derived NPM : {self.use_derived_matrix_RGB_to_XYZ}\n"
f"Use Derived NPM -1 : {self.use_derived_matrix_XYZ_to_RGB}"
)
[docs] def __repr__(self) -> str:
"""
Return an (almost) evaluable string representation of the *RGB*
colourspace.
Returns
-------
:class`str`
(Almost) evaluable string representation.
Examples
--------
>>> p = np.array(
... [0.73470, 0.26530, 0.00000, 1.00000, 0.00010, -0.07700])
>>> whitepoint = np.array([0.32168, 0.33767])
>>> matrix_RGB_to_XYZ = np.identity(3)
>>> matrix_XYZ_to_RGB = np.identity(3)
>>> cctf_encoding = lambda x: x
>>> cctf_decoding = lambda x: x
>>> RGB_Colourspace('RGB Colourspace', p, whitepoint, 'ACES',
... matrix_RGB_to_XYZ, matrix_XYZ_to_RGB,
... cctf_encoding, cctf_decoding)
... # doctest: +ELLIPSIS
RGB_Colourspace(RGB Colourspace,
[[ 7.34700000e-01, 2.65300000e-01],
[ 0.00000000e+00, 1.00000000e+00],
[ 1.00000000e-04, -7.70000000e-02]],
[ 0.32168, 0.33767],
ACES,
[[ 1., 0., 0.],
[ 0., 1., 0.],
[ 0., 0., 1.]],
[[ 1., 0., 0.],
[ 0., 1., 0.],
[ 0., 0., 1.]],
<function <lambda> at 0x...>,
<function <lambda> at 0x...>,
False,
False)
"""
def _indent_array(a: Optional[NDArray]) -> str:
"""Indent given array evaluable string representation."""
representation = repr(a).replace(" [", f"{' ' * 11}[")
representation = representation.replace("array(", " " * 16)
return representation.replace(")", "")
indentation = " " * 16
return (
f"RGB_Colourspace({self.name},\n"
f"{_indent_array(self.primaries)},\n"
f"{_indent_array(self.whitepoint)},\n"
f"{indentation}{self.whitepoint_name},\n"
f"{_indent_array(self.matrix_RGB_to_XYZ)},\n"
f"{_indent_array(self.matrix_XYZ_to_RGB)},\n"
f"{indentation}{self.cctf_encoding},\n"
f"{indentation}{self.cctf_decoding},\n"
f"{indentation}{self.use_derived_matrix_RGB_to_XYZ},\n"
f"{indentation}{self.use_derived_matrix_XYZ_to_RGB})"
)
def _derive_transformation_matrices(self):
"""
Compute the derived transformations matrices, the normalised primary
matrix and its inverse.
"""
if hasattr(self, "_primaries") and hasattr(self, "_whitepoint"):
if self._primaries is not None and self._whitepoint is not None:
npm = normalised_primary_matrix(
self._primaries, self._whitepoint
)
self._derived_matrix_RGB_to_XYZ = npm
self._derived_matrix_XYZ_to_RGB = np.linalg.inv(npm)
[docs] def chromatically_adapt(
self,
whitepoint: ArrayLike,
whitepoint_name: Optional[str] = None,
chromatic_adaptation_transform: Union[
Literal[
"Bianco 2010",
"Bianco PC 2010",
"Bradford",
"CAT02 Brill 2008",
"CAT02",
"CAT16",
"CMCCAT2000",
"CMCCAT97",
"Fairchild",
"Sharp",
"Von Kries",
"XYZ Scaling",
],
str,
] = "CAT02",
) -> RGB_Colourspace:
"""
Chromatically adapt the *RGB* colourspace *primaries* :math:`xy`
chromaticity coordinates from *RGB* colourspace whitepoint to reference
``whitepoint``.
Parameters
----------
whitepoint
Reference illuminant / whitepoint :math:`xy` chromaticity
coordinates.
whitepoint_name
Reference illuminant / whitepoint name.
chromatic_adaptation_transform
*Chromatic adaptation* transform.
Returns
-------
:class:`colour.RGB_Colourspace`
Chromatically adapted *RGB* colourspace.
Examples
--------
>>> p = np.array(
... [0.73470, 0.26530, 0.00000, 1.00000, 0.00010, -0.07700])
>>> w_t = np.array([0.32168, 0.33767])
>>> w_r = np.array([0.31270, 0.32900])
>>> colourspace = RGB_Colourspace('RGB Colourspace', p, w_t, 'D65')
>>> print(colourspace.chromatically_adapt(w_r, 'D50', 'Bradford'))
... # doctest: +ELLIPSIS
RGB Colourspace - Chromatically Adapted to 'D50'
------------------------------------------------
<BLANKLINE>
Primaries : [[ 0.73485524 0.26422533]
[-0.00617091 1.01131496]
[ 0.01596756 -0.0642355 ]]
Whitepoint : [ 0.3127 0.329 ]
Whitepoint Name : D50
Encoding CCTF : None
Decoding CCTF : None
NPM : None
NPM -1 : None
Derived NPM : [[ 0.93827985 -0.00445145 0.01662752]
[ 0.33736889 0.72952157 -0.06689046]
[ 0.00117395 -0.00371071 1.09159451]]
Derived NPM -1 : [[ 1.06349549 0.00640891 -0.01580679]
[-0.49207413 1.36822341 0.09133709]
[-0.00281646 0.00464417 0.91641857]]
Use Derived NPM : True
Use Derived NPM -1 : True
"""
colourspace = self.copy()
colourspace.primaries = chromatically_adapted_primaries(
colourspace.primaries,
colourspace.whitepoint,
whitepoint,
chromatic_adaptation_transform,
)
colourspace.whitepoint = whitepoint # type: ignore[assignment]
colourspace.whitepoint_name = whitepoint_name
colourspace._matrix_RGB_to_XYZ = None
colourspace._matrix_XYZ_to_RGB = None
colourspace._derive_transformation_matrices()
colourspace.use_derived_transformation_matrices()
colourspace.name = (
f"{colourspace.name} - Chromatically Adapted to "
f"{cast(str, optional(whitepoint_name, whitepoint))!r}"
)
return colourspace
[docs] def copy(self) -> RGB_Colourspace:
"""
Return a copy of the *RGB* colourspace.
Returns
-------
:class:`colour.RGB_Colourspace`
*RGB* colourspace copy.
"""
return deepcopy(self)
[docs]def XYZ_to_RGB(
XYZ: ArrayLike,
illuminant_XYZ: ArrayLike,
illuminant_RGB: ArrayLike,
matrix_XYZ_to_RGB: ArrayLike,
chromatic_adaptation_transform: Union[
Literal[
"Bianco 2010",
"Bianco PC 2010",
"Bradford",
"CAT02 Brill 2008",
"CAT02",
"CAT16",
"CMCCAT2000",
"CMCCAT97",
"Fairchild",
"Sharp",
"Von Kries",
"XYZ Scaling",
],
str,
] = "CAT02",
cctf_encoding: Optional[Callable] = None,
) -> NDArray:
"""
Convert from *CIE XYZ* tristimulus values to *RGB* colourspace array.
Parameters
----------
XYZ
*CIE XYZ* tristimulus values.
illuminant_XYZ
*CIE xy* chromaticity coordinates or *CIE xyY* colourspace array of the
*illuminant* for the input *CIE XYZ* tristimulus values.
illuminant_RGB
*CIE xy* chromaticity coordinates or *CIE xyY* colourspace array of the
*illuminant* for the output *RGB* colourspace array.
matrix_XYZ_to_RGB
Matrix converting the *CIE XYZ* tristimulus values to *RGB* colourspace
array, i.e. the inverse *Normalised Primary Matrix* (NPM).
chromatic_adaptation_transform
*Chromatic adaptation* transform, if *None* no chromatic adaptation is
performed.
cctf_encoding
Encoding colour component transfer function (Encoding CCTF) or
opto-electronic transfer function (OETF).
Returns
-------
:class:`numpy.ndarray`
*RGB* colourspace array.
Notes
-----
+--------------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+====================+=======================+===============+
| ``XYZ`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
| ``illuminant_XYZ`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
| ``illuminant_RGB`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
+--------------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+====================+=======================+===============+
| ``RGB`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
Examples
--------
>>> XYZ = np.array([0.21638819, 0.12570000, 0.03847493])
>>> illuminant_XYZ = np.array([0.34570, 0.35850])
>>> illuminant_RGB = np.array([0.31270, 0.32900])
>>> chromatic_adaptation_transform = 'Bradford'
>>> matrix_XYZ_to_RGB = np.array(
... [[3.24062548, -1.53720797, -0.49862860],
... [-0.96893071, 1.87575606, 0.04151752],
... [0.05571012, -0.20402105, 1.05699594]]
... )
>>> XYZ_to_RGB(XYZ, illuminant_XYZ, illuminant_RGB, matrix_XYZ_to_RGB,
... chromatic_adaptation_transform) # doctest: +ELLIPSIS
array([ 0.4559557..., 0.0303970..., 0.0408724...])
"""
XYZ = to_domain_1(XYZ)
if chromatic_adaptation_transform is not None:
M_CAT = matrix_chromatic_adaptation_VonKries(
xyY_to_XYZ(xy_to_xyY(illuminant_XYZ)),
xyY_to_XYZ(xy_to_xyY(illuminant_RGB)),
transform=chromatic_adaptation_transform,
)
XYZ = vector_dot(M_CAT, XYZ)
RGB = vector_dot(matrix_XYZ_to_RGB, XYZ)
if cctf_encoding is not None:
with domain_range_scale("ignore"):
RGB = cctf_encoding(RGB)
return from_range_1(RGB)
[docs]def RGB_to_XYZ(
RGB: ArrayLike,
illuminant_RGB: ArrayLike,
illuminant_XYZ: ArrayLike,
matrix_RGB_to_XYZ: ArrayLike,
chromatic_adaptation_transform: Union[
Literal[
"Bianco 2010",
"Bianco PC 2010",
"Bradford",
"CAT02 Brill 2008",
"CAT02",
"CAT16",
"CMCCAT2000",
"CMCCAT97",
"Fairchild",
"Sharp",
"Von Kries",
"XYZ Scaling",
],
str,
] = "CAT02",
cctf_decoding: Optional[Callable] = None,
) -> NDArray:
"""
Convert given *RGB* colourspace array to *CIE XYZ* tristimulus values.
Parameters
----------
RGB
*RGB* colourspace array.
illuminant_RGB
*CIE xy* chromaticity coordinates or *CIE xyY* colourspace array of the
*illuminant* for the input *RGB* colourspace array.
illuminant_XYZ
*CIE xy* chromaticity coordinates or *CIE xyY* colourspace array of the
*illuminant* for the output *CIE XYZ* tristimulus values.
matrix_RGB_to_XYZ
Matrix converting the *RGB* colourspace array to *CIE XYZ* tristimulus
values, i.e. the *Normalised Primary Matrix* (NPM).
chromatic_adaptation_transform
*Chromatic adaptation* transform, if *None* no chromatic adaptation is
performed.
cctf_decoding
Decoding colour component transfer function (Decoding CCTF) or
electro-optical transfer function (EOTF).
Returns
-------
:class:`numpy.ndarray`
*CIE XYZ* tristimulus values.
Notes
-----
+--------------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+====================+=======================+===============+
| ``RGB`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
| ``illuminant_XYZ`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
| ``illuminant_RGB`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
+--------------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+====================+=======================+===============+
| ``XYZ`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
Examples
--------
>>> RGB = np.array([0.45595571, 0.03039702, 0.04087245])
>>> illuminant_RGB = np.array([0.31270, 0.32900])
>>> illuminant_XYZ = np.array([0.34570, 0.35850])
>>> chromatic_adaptation_transform = 'Bradford'
>>> matrix_RGB_to_XYZ = np.array(
... [[0.41240000, 0.35760000, 0.18050000],
... [0.21260000, 0.71520000, 0.07220000],
... [0.01930000, 0.11920000, 0.95050000]]
... )
>>> RGB_to_XYZ(RGB, illuminant_RGB, illuminant_XYZ, matrix_RGB_to_XYZ,
... chromatic_adaptation_transform) # doctest: +ELLIPSIS
array([ 0.2163881..., 0.1257 , 0.0384749...])
"""
RGB = to_domain_1(RGB)
if cctf_decoding is not None:
with domain_range_scale("ignore"):
RGB = cctf_decoding(RGB)
XYZ = vector_dot(matrix_RGB_to_XYZ, RGB)
if chromatic_adaptation_transform is not None:
M_CAT = matrix_chromatic_adaptation_VonKries(
xyY_to_XYZ(xy_to_xyY(illuminant_RGB)),
xyY_to_XYZ(xy_to_xyY(illuminant_XYZ)),
transform=chromatic_adaptation_transform,
)
XYZ = vector_dot(M_CAT, XYZ)
return from_range_1(XYZ)
[docs]def matrix_RGB_to_RGB(
input_colourspace: RGB_Colourspace,
output_colourspace: RGB_Colourspace,
chromatic_adaptation_transform: Union[
Literal[
"Bianco 2010",
"Bianco PC 2010",
"Bradford",
"CAT02 Brill 2008",
"CAT02",
"CAT16",
"CMCCAT2000",
"CMCCAT97",
"Fairchild",
"Sharp",
"Von Kries",
"XYZ Scaling",
],
str,
] = "CAT02",
) -> NDArray:
"""
Compute the matrix :math:`M` converting from given input *RGB*
colourspace to output *RGB* colourspace using given *chromatic
adaptation* method.
Parameters
----------
input_colourspace
*RGB* input colourspace.
output_colourspace
*RGB* output colourspace.
chromatic_adaptation_transform
*Chromatic adaptation* transform, if *None* no chromatic adaptation is
performed.
Returns
-------
:class:`numpy.ndarray`
Conversion matrix :math:`M`.
Examples
--------
>>> from colour.models import (
... RGB_COLOURSPACE_sRGB, RGB_COLOURSPACE_PROPHOTO_RGB)
>>> matrix_RGB_to_RGB(RGB_COLOURSPACE_sRGB, RGB_COLOURSPACE_PROPHOTO_RGB)
... # doctest: +ELLIPSIS
array([[ 0.5288241..., 0.3340609..., 0.1373616...],
[ 0.0975294..., 0.8790074..., 0.0233981...],
[ 0.0163599..., 0.1066124..., 0.8772485...]])
"""
M = input_colourspace.matrix_RGB_to_XYZ
if chromatic_adaptation_transform is not None:
M_CAT = matrix_chromatic_adaptation_VonKries(
xy_to_XYZ(input_colourspace.whitepoint),
xy_to_XYZ(output_colourspace.whitepoint),
chromatic_adaptation_transform,
)
M = matrix_dot(M_CAT, input_colourspace.matrix_RGB_to_XYZ)
M = matrix_dot(output_colourspace.matrix_XYZ_to_RGB, M)
return M
[docs]def RGB_to_RGB(
RGB: ArrayLike,
input_colourspace: RGB_Colourspace,
output_colourspace: RGB_Colourspace,
chromatic_adaptation_transform: Union[
Literal[
"Bianco 2010",
"Bianco PC 2010",
"Bradford",
"CAT02 Brill 2008",
"CAT02",
"CAT16",
"CMCCAT2000",
"CMCCAT97",
"Fairchild",
"Sharp",
"Von Kries",
"XYZ Scaling",
],
str,
] = "CAT02",
apply_cctf_decoding: Boolean = False,
apply_cctf_encoding: Boolean = False,
**kwargs: Any,
) -> NDArray:
"""
Convert given *RGB* colourspace array from given input *RGB* colourspace
to output *RGB* colourspace using given *chromatic adaptation* method.
Parameters
----------
RGB
*RGB* colourspace array.
input_colourspace
*RGB* input colourspace.
output_colourspace
*RGB* output colourspace.
chromatic_adaptation_transform
*Chromatic adaptation* transform, if *None* no chromatic adaptation is
performed.
apply_cctf_decoding
Apply input colourspace decoding colour component transfer function /
electro-optical transfer function.
apply_cctf_encoding
Apply output colourspace encoding colour component transfer function /
opto-electronic transfer function.
Other Parameters
----------------
kwargs
Keywords arguments for the colour component transfer functions.
Returns
-------
:class:`numpy.ndarray`
*RGB* colourspace array.
Notes
-----
+--------------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+====================+=======================+===============+
| ``RGB`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
+--------------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+====================+=======================+===============+
| ``RGB`` | [0, 1] | [0, 1] |
+--------------------+-----------------------+---------------+
Examples
--------
>>> from colour.models import (
... RGB_COLOURSPACE_sRGB, RGB_COLOURSPACE_PROPHOTO_RGB)
>>> RGB = np.array([0.45595571, 0.03039702, 0.04087245])
>>> RGB_to_RGB(RGB, RGB_COLOURSPACE_sRGB, RGB_COLOURSPACE_PROPHOTO_RGB)
... # doctest: +ELLIPSIS
array([ 0.2568891..., 0.0721446..., 0.0465553...])
"""
RGB = to_domain_1(RGB)
if apply_cctf_decoding and input_colourspace.cctf_decoding is not None:
with domain_range_scale("ignore"):
RGB = input_colourspace.cctf_decoding(
RGB, **filter_kwargs(input_colourspace.cctf_decoding, **kwargs)
)
M = matrix_RGB_to_RGB(
input_colourspace, output_colourspace, chromatic_adaptation_transform
)
RGB = vector_dot(M, RGB)
if apply_cctf_encoding and output_colourspace.cctf_encoding is not None:
with domain_range_scale("ignore"):
RGB = output_colourspace.cctf_encoding(
RGB,
**filter_kwargs(output_colourspace.cctf_encoding, **kwargs),
)
return from_range_1(RGB)