"""
References
----------
- :cite:`Abasi2020a` : Abasi, S., Amani Tehran, M., & Fairchild, M. D. (2020).
Distance metrics for very large color differences. Color Research &
Application, 45(2), 208-223. doi:10.1002/col.22451
- :cite:`ASTMInternational2007` : ASTM International. (2007). ASTM D2244-07 -
Standard Practice for Calculation of Color Tolerances and Color Differences
from Instrumentally Measured Color Coordinates: Vol. i (pp. 1-10).
doi:10.1520/D2244-16
- :cite:`InternationalTelecommunicationUnion2019` : International
Telecommunication Union. (2019). Recommendation ITU-R BT.2124-0 -
Objective metric for the assessment of the potential visibility of colour
differences in television (pp. 1-36). http://www.itu.int/dms_pubrec/itu-r/\
rec/bt/R-REC-BT.470-6-199811-S!!PDF-E.pdf
- :cite:`Li2017` : Li, C., Li, Z., Wang, Z., Xu, Y., Luo, M. R., Cui, G.,
Melgosa, M., Brill, M. H., & Pointer, M. (2017). Comprehensive color
solutions: CAM16, CAT16, and CAM16-UCS. Color Research & Application,
42(6), 703-718. doi:10.1002/col.22131
- :cite:`Lindbloom2003c` : Lindbloom, B. (2003). Delta E (CIE 1976).
Retrieved February 24, 2014, from
http://brucelindbloom.com/Eqn_DeltaE_CIE76.html
- :cite:`Lindbloom2009f` : Lindbloom, B. (2009). Delta E (CMC). Retrieved
February 24, 2014, from http://brucelindbloom.com/Eqn_DeltaE_CMC.html
- :cite:`Lindbloom2011a` : Lindbloom, B. (2011). Delta E (CIE 1994).
Retrieved February 24, 2014, from
http://brucelindbloom.com/Eqn_DeltaE_CIE94.html
- :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
- :cite:`Melgosa2013b` : Melgosa, M. (2013). CIE / ISO new standard:
CIEDE2000. http://www.color.org/events/colorimetry/\
Melgosa_CIEDE2000_Workshop-July4.pdf
- :cite:`Wikipedia2008b` : Wikipedia. (2008). Color difference. Retrieved
August 29, 2014, from http://en.wikipedia.org/wiki/Color_difference
"""
from __future__ import annotations
from colour.hints import Any, ArrayLike, NDArrayFloat, LiteralDeltaEMethod
from colour.utilities import (
CanonicalMapping,
filter_kwargs,
validate_method,
)
from .cam02_ucs import delta_E_CAM02LCD, delta_E_CAM02SCD, delta_E_CAM02UCS
from .cam16_ucs import delta_E_CAM16LCD, delta_E_CAM16SCD, delta_E_CAM16UCS
from .delta_e import (
JND_CIE1976,
delta_E_CIE1976,
delta_E_CIE1994,
delta_E_CIE2000,
delta_E_CMC,
delta_E_ITP,
delta_E_HyAB,
delta_E_HyCH,
)
from .din99 import delta_E_DIN99
from .huang2015 import power_function_Huang2015
from .stress import index_stress_Garcia2007, INDEX_STRESS_METHODS, index_stress
__all__ = [
"delta_E_CAM02LCD",
"delta_E_CAM02SCD",
"delta_E_CAM02UCS",
]
__all__ += [
"delta_E_CAM16LCD",
"delta_E_CAM16SCD",
"delta_E_CAM16UCS",
]
__all__ += [
"JND_CIE1976",
"delta_E_CIE1976",
"delta_E_CIE1994",
"delta_E_CIE2000",
"delta_E_CMC",
"delta_E_ITP",
"delta_E_HyAB",
"delta_E_HyCH",
]
__all__ += [
"delta_E_DIN99",
]
__all__ += [
"power_function_Huang2015",
]
__all__ += [
"index_stress_Garcia2007",
"INDEX_STRESS_METHODS",
"index_stress",
]
DELTA_E_METHODS: CanonicalMapping = CanonicalMapping(
{
"CIE 1976": delta_E_CIE1976,
"CIE 1994": delta_E_CIE1994,
"CIE 2000": delta_E_CIE2000,
"CMC": delta_E_CMC,
"ITP": delta_E_ITP,
"CAM02-LCD": delta_E_CAM02LCD,
"CAM02-SCD": delta_E_CAM02SCD,
"CAM02-UCS": delta_E_CAM02UCS,
"CAM16-LCD": delta_E_CAM16LCD,
"CAM16-SCD": delta_E_CAM16SCD,
"CAM16-UCS": delta_E_CAM16UCS,
"DIN99": delta_E_DIN99,
"HyAB": delta_E_HyAB,
"HyCH": delta_E_HyCH,
}
)
DELTA_E_METHODS.__doc__ = """
Supported :math:`\\Delta E_{ab}` computation methods.
References
----------
:cite:`ASTMInternational2007`, :cite:`Abasi2020a`, :cite:`Li2017`,
:cite:`Lindbloom2003c`, :cite:`Lindbloom2011a`, :cite:`Lindbloom2009f`,
:cite:`Luo2006b`, :cite:`Melgosa2013b`, :cite:`Wikipedia2008b`
Aliases:
- 'cie1976': 'CIE 1976'
- 'cie1994': 'CIE 1994'
- 'cie2000': 'CIE 2000'
"""
DELTA_E_METHODS["cie1976"] = DELTA_E_METHODS["CIE 1976"]
DELTA_E_METHODS["cie1994"] = DELTA_E_METHODS["CIE 1994"]
DELTA_E_METHODS["cie2000"] = DELTA_E_METHODS["CIE 2000"]
[docs]
def delta_E(
a: ArrayLike,
b: ArrayLike,
method: LiteralDeltaEMethod | str = "CIE 2000",
**kwargs: Any,
) -> NDArrayFloat:
"""
Return the difference :math:`\\Delta E_{ab}` between two given
*CIE L\\*a\\*b\\**, :math:`IC_TC_P`, or :math:`J'a'b'` colourspace arrays
using given method.
Parameters
----------
a
*CIE L\\*a\\*b\\**, :math:`IC_TC_P`, or :math:`J'a'b'` colourspace
array :math:`a`.
b
*CIE L\\*a\\*b\\**, :math:`IC_TC_P`, or :math:`J'a'b'` colourspace
array :math:`b`.
method
Computation method.
Other Parameters
----------------
c
{:func:`colour.difference.delta_E_CIE2000`},
Chroma weighting factor.
l
{:func:`colour.difference.delta_E_CIE2000`},
Lightness weighting factor.
textiles
{:func:`colour.difference.delta_E_CIE1994`,
:func:`colour.difference.delta_E_CIE2000`,
:func:`colour.difference.delta_E_DIN99`},
Textiles application specific parametric factors
:math:`k_L=2,\\ k_C=k_H=1,\\ k_1=0.048,\\ k_2=0.014,\\ k_E=2,\
\\ k_CH=0.5` weights are used instead of
:math:`k_L=k_C=k_H=1,\\ k_1=0.045,\\ k_2=0.015,\\ k_E=k_CH=1.0`.
Returns
-------
:class:`numpy.ndarray`
Colour difference :math:`\\Delta E_{ab}`.
References
----------
:cite:`ASTMInternational2007`,
:cite:`InternationalTelecommunicationUnion2019`, :cite:`Li2017`,
:cite:`Lindbloom2003c`, :cite:`Lindbloom2011a`, :cite:`Lindbloom2009f`,
:cite:`Luo2006b`, :cite:`Melgosa2013b`, :cite:`Wikipedia2008b`
Examples
--------
>>> import numpy as np
>>> a = np.array([48.99183622, -0.10561667, 400.65619925])
>>> b = np.array([50.65907324, -0.11671910, 402.82235718])
>>> delta_E(a, b) # doctest: +ELLIPSIS
1.6709303...
>>> delta_E(a, b, method="CIE 2000") # doctest: +ELLIPSIS
1.6709303...
>>> delta_E(a, b, method="CIE 1976") # doctest: +ELLIPSIS
2.7335037...
>>> delta_E(a, b, method="CIE 1994") # doctest: +ELLIPSIS
1.6711191...
>>> delta_E(a, b, method="CIE 1994", textiles=True)
... # doctest: +ELLIPSIS
0.8404677...
>>> delta_E(a, b, method="DIN99") # doctest: +ELLIPSIS
1.5591089...
>>> a = np.array([0.4885468072, -0.04739350675, 0.07475401302])
>>> b = np.array([0.4899203231, -0.04567508203, 0.07361341775])
>>> delta_E(a, b, method="ITP") # doctest: +ELLIPSIS
1.42657228...
>>> a = np.array([54.90433134, -0.08450395, -0.06854831])
>>> b = np.array([54.90433134, -0.08442362, -0.06848314])
>>> delta_E(a, b, method="CAM02-UCS") # doctest: +ELLIPSIS
0.0001034...
>>> delta_E(a, b, method="CAM16-LCD") # doctest: +ELLIPSIS
0.0001034...
>>> a = np.array([39.91531343, 51.16658481, 146.12933781])
>>> b = np.array([53.12207516, -39.92365056, 249.54831278])
>>> delta_E(a, b, method="HyAB") # doctest: +ELLIPSIS
151.0215481...
>>> a = np.array([39.91531343, 51.16658481, 146.12933781])
>>> b = np.array([53.12207516, -39.92365056, 249.54831278])
>>> delta_E(a, b, method="HyCH") # doctest: +ELLIPSIS
48.66427941...
"""
method = validate_method(method, tuple(DELTA_E_METHODS))
function = DELTA_E_METHODS[method]
return function(a, b, **filter_kwargs(function, **kwargs))
__all__ += [
"DELTA_E_METHODS",
"delta_E",
]
