"""
:math:`\\Delta E'` - Delta E Colour Difference - Luo, Cui and Li (2006)
=======================================================================
Define the :math:`\\Delta E'` colour difference computation objects based on
*Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, and *CAM02-UCS* colourspaces:
- :func:`colour.difference.delta_E_CAM02LCD`
- :func:`colour.difference.delta_E_CAM02SCD`
- :func:`colour.difference.delta_E_CAM02UCS`
References
----------
- :cite:`Luo2006b` : Luo, M. Ronnier, Cui, G., & Li, C. (2006). Uniform
colour spaces based on CIECAM02 colour appearance model. Color Research &
Application, 31(4), 320-330. doi:10.1002/col.20227
"""
from __future__ import annotations
import numpy as np
from colour.hints import ArrayLike, NDArrayFloat
from colour.models.cam02_ucs import COEFFICIENTS_UCS_LUO2006
from colour.utilities import as_float, tsplit
__author__ = "Colour Developers"
__copyright__ = "Copyright 2013 Colour Developers"
__license__ = "BSD-3-Clause - https://opensource.org/licenses/BSD-3-Clause"
__maintainer__ = "Colour Developers"
__email__ = "colour-developers@colour-science.org"
__status__ = "Production"
__all__ = [
"delta_E_Luo2006",
"delta_E_CAM02LCD",
"delta_E_CAM02SCD",
"delta_E_CAM02UCS",
]
def delta_E_Luo2006(
Jpapbp_1: ArrayLike, Jpapbp_2: ArrayLike, coefficients: ArrayLike
) -> NDArrayFloat:
"""
Return the difference :math:`\\Delta E'` between two given
*Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or *CAM02-UCS* colourspaces
:math:`J'a'b'` arrays.
Parameters
----------
Jpapbp_1
Standard / reference *Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or
*CAM02-UCS* colourspaces :math:`J'a'b'` array.
Jpapbp_2
Sample / test *Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or
*CAM02-UCS* colourspaces :math:`J'a'b'` array.
coefficients
Coefficients of one of the *Luo et al. (2006)* *CAM02-LCD*,
*CAM02-SCD*, or *CAM02-UCS* colourspaces.
Returns
-------
:class:`numpy.ndarray`
Colour difference :math:`\\Delta E'`.
Warnings
--------
The :math:`J'a'b'` array should have been computed with a
*Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or *CAM02-UCS* colourspace
and not with the *CIE L\\*a\\*b\\** colourspace.
Notes
-----
+--------------+------------------------+--------------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+==============+========================+====================+
| ``Jpapbp_1`` | ``Jp_1`` : [0, 100] | ``Jp_1`` : [0, 1] |
| | | |
| | ``ap_1`` : [-100, 100] | ``ap_1`` : [-1, 1] |
| | | |
| | ``bp_1`` : [-100, 100] | ``bp_1`` : [-1, 1] |
+--------------+------------------------+--------------------+
| ``Jpapbp_2`` | ``Jp_2`` : [0, 100] | ``Jp_2`` : [0, 1] |
| | | |
| | ``ap_2`` : [-100, 100] | ``ap_2`` : [-1, 1] |
| | | |
| | ``bp_2`` : [-100, 100] | ``bp_2`` : [-1, 1] |
+--------------+------------------------+--------------------+
Examples
--------
>>> Jpapbp_1 = np.array([54.90433134, -0.08450395, -0.06854831])
>>> Jpapbp_2 = np.array([54.80352754, -3.96940084, -13.57591013])
>>> delta_E_Luo2006(Jpapbp_1, Jpapbp_2, COEFFICIENTS_UCS_LUO2006["CAM02-LCD"])
... # doctest: +ELLIPSIS
14.0555464...
"""
J_p_1, a_p_1, b_p_1 = tsplit(Jpapbp_1)
J_p_2, a_p_2, b_p_2 = tsplit(Jpapbp_2)
K_L, _c_1, _c_2 = tsplit(coefficients)
d_E = np.sqrt(
((J_p_1 - J_p_2) / K_L) ** 2 + (a_p_1 - a_p_2) ** 2 + (b_p_1 - b_p_2) ** 2
)
return as_float(d_E)
[docs]
def delta_E_CAM02LCD(Jpapbp_1: ArrayLike, Jpapbp_2: ArrayLike) -> NDArrayFloat:
"""
Return the difference :math:`\\Delta E'` between two given
*Luo et al. (2006)* *CAM02-LCD* colourspaces :math:`J'a'b'` arrays.
Parameters
----------
Jpapbp_1
Standard / reference *Luo et al. (2006)* *CAM02-LCD* colourspaces
:math:`J'a'b'` array.
Jpapbp_2
Sample / test *Luo et al. (2006)* *CAM02-LCD* colourspaces
:math:`J'a'b'` array.
Returns
-------
:class:`numpy.ndarray`
Colour difference :math:`\\Delta E'`.
Warnings
--------
The :math:`J'a'b'` array should have been computed with a
*Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or *CAM02-UCS* colourspace
and not with the *CIE L\\*a\\*b\\** colourspace.
Notes
-----
+--------------+------------------------+--------------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+==============+========================+====================+
| ``Jpapbp_1`` | ``Jp_1`` : [0, 100] | ``Jp_1`` : [0, 1] |
| | | |
| | ``ap_1`` : [-100, 100] | ``ap_1`` : [-1, 1] |
| | | |
| | ``bp_1`` : [-100, 100] | ``bp_1`` : [-1, 1] |
+--------------+------------------------+--------------------+
| ``Jpapbp_2`` | ``Jp_2`` : [0, 100] | ``Jp_2`` : [0, 1] |
| | | |
| | ``ap_2`` : [-100, 100] | ``ap_2`` : [-1, 1] |
| | | |
| | ``bp_2`` : [-100, 100] | ``bp_2`` : [-1, 1] |
+--------------+------------------------+--------------------+
References
----------
:cite:`Luo2006b`
Examples
--------
>>> Jpapbp_1 = np.array([54.90433134, -0.08450395, -0.06854831])
>>> Jpapbp_2 = np.array([54.80352754, -3.96940084, -13.57591013])
>>> delta_E_CAM02LCD(Jpapbp_1, Jpapbp_2) # doctest: +ELLIPSIS
14.0555464...
"""
return delta_E_Luo2006(Jpapbp_1, Jpapbp_2, COEFFICIENTS_UCS_LUO2006["CAM02-LCD"])
[docs]
def delta_E_CAM02SCD(Jpapbp_1: ArrayLike, Jpapbp_2: ArrayLike) -> NDArrayFloat:
"""
Return the difference :math:`\\Delta E'` between two given
*Luo et al. (2006)* *CAM02-SCD* colourspaces :math:`J'a'b'` arrays.
Parameters
----------
Jpapbp_1
Standard / reference *Luo et al. (2006)* *CAM02-SCD* colourspaces
:math:`J'a'b'` array.
Jpapbp_2
Sample / test *Luo et al. (2006)* *CAM02-SCD* colourspaces
:math:`J'a'b'` array.
Returns
-------
:class:`numpy.ndarray`
Colour difference :math:`\\Delta E'`.
Warnings
--------
The :math:`J'a'b'` array should have been computed with a
*Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or *CAM02-UCS* colourspace
and not with the *CIE L\\*a\\*b\\** colourspace.
Notes
-----
+--------------+------------------------+--------------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+==============+========================+====================+
| ``Jpapbp_1`` | ``Jp_1`` : [0, 100] | ``Jp_1`` : [0, 1] |
| | | |
| | ``ap_1`` : [-100, 100] | ``ap_1`` : [-1, 1] |
| | | |
| | ``bp_1`` : [-100, 100] | ``bp_1`` : [-1, 1] |
+--------------+------------------------+--------------------+
| ``Jpapbp_2`` | ``Jp_2`` : [0, 100] | ``Jp_2`` : [0, 1] |
| | | |
| | ``ap_2`` : [-100, 100] | ``ap_2`` : [-1, 1] |
| | | |
| | ``bp_2`` : [-100, 100] | ``bp_2`` : [-1, 1] |
+--------------+------------------------+--------------------+
References
----------
:cite:`Luo2006b`
Examples
--------
>>> Jpapbp_1 = np.array([54.90433134, -0.08450395, -0.06854831])
>>> Jpapbp_2 = np.array([54.80352754, -3.96940084, -13.57591013])
>>> delta_E_CAM02SCD(Jpapbp_1, Jpapbp_2) # doctest: +ELLIPSIS
14.0551718...
"""
return delta_E_Luo2006(Jpapbp_1, Jpapbp_2, COEFFICIENTS_UCS_LUO2006["CAM02-SCD"])
[docs]
def delta_E_CAM02UCS(Jpapbp_1: ArrayLike, Jpapbp_2: ArrayLike) -> NDArrayFloat:
"""
Return the difference :math:`\\Delta E'` between two given
*Luo et al. (2006)* *CAM02-UCS* colourspaces :math:`J'a'b'` arrays.
Parameters
----------
Jpapbp_1
Standard / reference *Luo et al. (2006)* *CAM02-UCS* colourspaces
:math:`J'a'b'` array.
Jpapbp_2
Sample / test *Luo et al. (2006)* *CAM02-UCS* colourspaces
:math:`J'a'b'` array.
Returns
-------
:class:`numpy.ndarray`
Colour difference :math:`\\Delta E'`.
Warnings
--------
The :math:`J'a'b'` array should have been computed with a
*Luo et al. (2006)* *CAM02-LCD*, *CAM02-SCD*, or *CAM02-UCS* colourspace
and not with the *CIE L\\*a\\*b\\** colourspace.
Notes
-----
+--------------+------------------------+--------------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+==============+========================+====================+
| ``Jpapbp_1`` | ``Jp_1`` : [0, 100] | ``Jp_1`` : [0, 1] |
| | | |
| | ``ap_1`` : [-100, 100] | ``ap_1`` : [-1, 1] |
| | | |
| | ``bp_1`` : [-100, 100] | ``bp_1`` : [-1, 1] |
+--------------+------------------------+--------------------+
| ``Jpapbp_2`` | ``Jp_2`` : [0, 100] | ``Jp_2`` : [0, 1] |
| | | |
| | ``ap_2`` : [-100, 100] | ``ap_2`` : [-1, 1] |
| | | |
| | ``bp_2`` : [-100, 100] | ``bp_2`` : [-1, 1] |
+--------------+------------------------+--------------------+
References
----------
:cite:`Luo2006b`
Examples
--------
>>> Jpapbp_1 = np.array([54.90433134, -0.08450395, -0.06854831])
>>> Jpapbp_2 = np.array([54.80352754, -3.96940084, -13.57591013])
>>> delta_E_CAM02UCS(Jpapbp_1, Jpapbp_2) # doctest: +ELLIPSIS
14.0552982...
"""
return delta_E_Luo2006(Jpapbp_1, Jpapbp_2, COEFFICIENTS_UCS_LUO2006["CAM02-UCS"])
