Source code for colour.appearance.kim2009

"""
Kim, Weyrich and Kautz (2009) Colour Appearance Model
=====================================================

Defines the *Kim, Weyrich and Kautz (2009)* colour appearance model objects:

-   :class:`colour.appearance.InductionFactors_Kim2009`
-   :attr:`colour.VIEWING_CONDITIONS_KIM2009`
-   :class:`colour.appearance.MediaParameters_Kim2009`
-   :attr:`colour.MEDIA_PARAMETERS_KIM2009`
-   :class:`colour.CAM_Specification_Kim2009`
-   :func:`colour.XYZ_to_Kim2009`
-   :func:`colour.Kim2009_to_XYZ`

References
----------
-   :cite:`Kim2009` : Kim, M., Weyrich, T., & Kautz, J. (2009). Modeling Human
    Color Perception under Extended Luminance Levels. ACM Transactions on
    Graphics, 28(3), 27:1--27:9. doi:10.1145/1531326.1531333
"""

from __future__ import annotations

import numpy as np
from collections import namedtuple
from dataclasses import astuple, dataclass, field

from colour.adaptation import CAT_CAT02
from colour.appearance.ciecam02 import (
    VIEWING_CONDITIONS_CIECAM02,
    CAT_INVERSE_CAT02,
    RGB_to_rgb,
    degree_of_adaptation,
    full_chromatic_adaptation_forward,
    full_chromatic_adaptation_inverse,
    hue_quadrature,
    rgb_to_RGB,
)
from colour.algebra import vector_dot, spow
from colour.hints import (
    ArrayLike,
    Boolean,
    Floating,
    FloatingOrArrayLike,
    FloatingOrNDArray,
    NDArray,
    Optional,
)
from colour.utilities import (
    CanonicalMapping,
    MixinDataclassArithmetic,
    as_float,
    as_float_array,
    from_range_100,
    from_range_degrees,
    has_only_nan,
    ones,
    to_domain_100,
    to_domain_degrees,
    tsplit,
    tstack,
)

__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__ = [
    "InductionFactors_Kim2009",
    "VIEWING_CONDITIONS_KIM2009",
    "MediaParameters_Kim2009",
    "MEDIA_PARAMETERS_KIM2009",
    "CAM_Specification_Kim2009",
    "XYZ_to_Kim2009",
    "Kim2009_to_XYZ",
]


[docs]class InductionFactors_Kim2009( namedtuple("InductionFactors_Kim2009", ("F", "c", "N_c")) ): """ *Kim, Weyrich and Kautz (2009)* colour appearance model induction factors. Parameters ---------- F Maximum degree of adaptation :math:`F`. c Exponential non-linearity :math:`c`. N_c Chromatic induction factor :math:`N_c`. Notes ----- - The *Kim, Weyrich and Kautz (2009)* colour appearance model induction factors are the same as *CIECAM02* colour appearance model. - The *Kim, Weyrich and Kautz (2009)* colour appearance model separates the surround modelled by the :class:`colour.appearance.InductionFactors_Kim2009` class instance from the media, modeled with the :class:`colour.appearance.MediaParameters_Kim2009` class instance. References ---------- :cite:`Kim2009` """
VIEWING_CONDITIONS_KIM2009: CanonicalMapping = CanonicalMapping( VIEWING_CONDITIONS_CIECAM02 ) VIEWING_CONDITIONS_KIM2009.__doc__ = """ Reference *Kim, Weyrich and Kautz (2009)* colour appearance model viewing conditions. References ---------- :cite:`Kim2009` """
[docs]class MediaParameters_Kim2009(namedtuple("MediaParameters_Kim2009", ("E",))): """ *Kim, Weyrich and Kautz (2009)* colour appearance model media parameters. Parameters ---------- E Lightness prediction modulating parameter :math:`E`. References ---------- :cite:`Kim2009` """ def __new__(cls, E): """ Return a new instance of the :class:`colour.appearance.MediaParameters_Kim2009` class. """ return super().__new__(cls, E)
MEDIA_PARAMETERS_KIM2009: CanonicalMapping = CanonicalMapping( { "High-luminance LCD Display": MediaParameters_Kim2009(1), "Transparent Advertising Media": MediaParameters_Kim2009(1.2175), "CRT Displays": MediaParameters_Kim2009(1.4572), "Reflective Paper": MediaParameters_Kim2009(1.7526), } ) MEDIA_PARAMETERS_KIM2009.__doc__ = """ Reference *Kim, Weyrich and Kautz (2009)* colour appearance model media parameters. References ---------- :cite:`Kim2009` Aliases: - 'bright_lcd_display': 'High-luminance LCD Display' - 'advertising_transparencies': 'Transparent Advertising Media' - 'crt': 'CRT Displays' - 'paper': 'Reflective Paper' """ MEDIA_PARAMETERS_KIM2009["bright_lcd_display"] = MEDIA_PARAMETERS_KIM2009[ "High-luminance LCD Display" ] MEDIA_PARAMETERS_KIM2009[ "advertising_transparencies" ] = MEDIA_PARAMETERS_KIM2009["Transparent Advertising Media"] MEDIA_PARAMETERS_KIM2009["crt"] = MEDIA_PARAMETERS_KIM2009["CRT Displays"] MEDIA_PARAMETERS_KIM2009["paper"] = MEDIA_PARAMETERS_KIM2009[ "Reflective Paper" ]
[docs]@dataclass class CAM_Specification_Kim2009(MixinDataclassArithmetic): """ Define the *Kim, Weyrich and Kautz (2009)* colour appearance model specification. Parameters ---------- J Correlate of *Lightness* :math:`J`. C Correlate of *chroma* :math:`C`. h *Hue* angle :math:`h` in degrees. s Correlate of *saturation* :math:`s`. Q Correlate of *brightness* :math:`Q`. M Correlate of *colourfulness* :math:`M`. H *Hue* :math:`h` quadrature :math:`H`. HC *Hue* :math:`h` composition :math:`H^C`. References ---------- :cite:`Kim2009` """ J: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) C: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) h: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) s: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) Q: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) M: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) H: Optional[FloatingOrNDArray] = field(default_factory=lambda: None) HC: Optional[FloatingOrNDArray] = field(default_factory=lambda: None)
[docs]def XYZ_to_Kim2009( XYZ: ArrayLike, XYZ_w: ArrayLike, L_A: FloatingOrArrayLike, media: MediaParameters_Kim2009 = MEDIA_PARAMETERS_KIM2009["CRT Displays"], surround: InductionFactors_Kim2009 = VIEWING_CONDITIONS_KIM2009["Average"], discount_illuminant: Boolean = False, n_c: Floating = 0.57, ) -> CAM_Specification_Kim2009: """ Compute the *Kim, Weyrich and Kautz (2009)* colour appearance model correlates from given *CIE XYZ* tristimulus values. Parameters ---------- XYZ *CIE XYZ* tristimulus values of test sample / stimulus. XYZ_w *CIE XYZ* tristimulus values of reference white. L_A Adapting field *luminance* :math:`L_A` in :math:`cd/m^2`, (often taken to be 20% of the luminance of a white object in the scene). media Media parameters. surround Surround viewing conditions induction factors. discount_illuminant Truth value indicating if the illuminant should be discounted. n_c Cone response sigmoidal curve modulating factor :math:`n_c`. Returns ------- :class:`colour.CAM_Specification_Kim2009` *Kim, Weyrich and Kautz (2009)* colour appearance model specification. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``XYZ`` | [0, 100] | [0, 1] | +------------+-----------------------+---------------+ | ``XYZ_w`` | [0, 100] | [0, 1] | +------------+-----------------------+---------------+ +---------------------------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +=================================+=======================+===============+ | ``CAM_Specification_Kim2009.J`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.C`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.h`` | [0, 360] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.s`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.Q`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.M`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.H`` | [0, 400] | [0, 1] | +---------------------------------+-----------------------+---------------+ References ---------- :cite:`Kim2009` Examples -------- >>> XYZ = np.array([19.01, 20.00, 21.78]) >>> XYZ_w = np.array([95.05, 100.00, 108.88]) >>> L_A = 318.31 >>> media = MEDIA_PARAMETERS_KIM2009['CRT Displays'] >>> surround = VIEWING_CONDITIONS_KIM2009['Average'] >>> XYZ_to_Kim2009(XYZ, XYZ_w, L_A, media, surround) ... # doctest: +ELLIPSIS CAM_Specification_Kim2009(J=28.8619089..., C=0.5592455..., \ h=219.0480667..., s=9.3837797..., Q=52.7138883..., M=0.4641738..., \ H=278.0602824..., HC=None) """ XYZ = to_domain_100(XYZ) XYZ_w = to_domain_100(XYZ_w) _X_w, Y_w, _Z_w = tsplit(XYZ_w) L_A = as_float_array(L_A) # Converting *CIE XYZ* tristimulus values to *CMCCAT2000* transform # sharpened *RGB* values. RGB = vector_dot(CAT_CAT02, XYZ) RGB_w = vector_dot(CAT_CAT02, XYZ_w) # Computing degree of adaptation :math:`D`. D = ( degree_of_adaptation(surround.F, L_A) if not discount_illuminant else ones(L_A.shape) ) # Computing full chromatic adaptation. XYZ_c = full_chromatic_adaptation_forward(RGB, RGB_w, Y_w, D) XYZ_wc = full_chromatic_adaptation_forward(RGB_w, RGB_w, Y_w, D) # Converting to *Hunt-Pointer-Estevez* colourspace. LMS = RGB_to_rgb(XYZ_c) LMS_w = RGB_to_rgb(XYZ_wc) # Cones absolute response. LMS_n_c = spow(LMS, n_c) LMS_w_n_c = spow(LMS_w, n_c) L_A_n_c = spow(L_A, n_c) LMS_p = LMS_n_c / (LMS_n_c + L_A_n_c) LMS_wp = LMS_w_n_c / (LMS_w_n_c + L_A_n_c) # Achromatic signal :math:`A` and :math:`A_w`. v_A = np.array([40, 20, 1]) A = np.sum(v_A * LMS_p, axis=-1) / 61 A_w = np.sum(v_A * LMS_wp, axis=-1) / 61 # Perceived *Lightness* :math:`J_p`. a_j, b_j, o_j, n_j = 0.89, 0.24, 0.65, 3.65 A_A_w = A / A_w J_p = spow( (-(A_A_w - b_j) * spow(o_j, n_j)) / (A_A_w - b_j - a_j), 1 / n_j ) # Computing the media dependent *Lightness* :math:`J`. J = 100 * (media.E * (J_p - 1) + 1) # Computing the correlate of *brightness* :math:`Q`. n_q = 0.1308 Q = J * spow(Y_w, n_q) # Opponent signals :math:`a` and :math:`b`. a = (1 / 11) * np.sum(np.array([11, -12, 1]) * LMS_p, axis=-1) b = (1 / 9) * np.sum(np.array([1, 1, -2]) * LMS_p, axis=-1) # Computing the correlate of *chroma* :math:`C`. a_k, n_k = 456.5, 0.62 C = a_k * spow(np.sqrt(a**2 + b**2), n_k) # Computing the correlate of *colourfulness* :math:`M`. a_m, b_m = 0.11, 0.61 M = C * (a_m * np.log10(Y_w) + b_m) # Computing the correlate of *saturation* :math:`s`. s = 100 * np.sqrt(M / Q) # Computing the *hue* angle :math:`h`. h = np.degrees(np.arctan2(b, a)) % 360 # Computing hue :math:`h` quadrature :math:`H`. H = hue_quadrature(h) return CAM_Specification_Kim2009( as_float(from_range_100(J)), as_float(from_range_100(C)), as_float(from_range_degrees(h)), as_float(from_range_100(s)), as_float(from_range_100(Q)), as_float(from_range_100(M)), as_float(from_range_degrees(H, 400)), None, )
[docs]def Kim2009_to_XYZ( specification: CAM_Specification_Kim2009, XYZ_w: ArrayLike, L_A: FloatingOrArrayLike, media: MediaParameters_Kim2009 = MEDIA_PARAMETERS_KIM2009["CRT Displays"], surround: InductionFactors_Kim2009 = VIEWING_CONDITIONS_KIM2009["Average"], discount_illuminant: Boolean = False, n_c: Floating = 0.57, ) -> NDArray: """ Convert from *Kim, Weyrich and Kautz (2009)* specification to *CIE XYZ* tristimulus values. Parameters ---------- specification *Kim, Weyrich and Kautz (2009)* colour appearance model specification. Correlate of *Lightness* :math:`J`, correlate of *chroma* :math:`C` or correlate of *colourfulness* :math:`M` and *hue* angle :math:`h` in degrees must be specified, e.g. :math:`JCh` or :math:`JMh`. XYZ_w *CIE XYZ* tristimulus values of reference white. L_A Adapting field *luminance* :math:`L_A` in :math:`cd/m^2`, (often taken to be 20% of the luminance of a white object in the scene). media Media parameters. surroundl Surround viewing conditions induction factors. discount_illuminant Discount the illuminant. n_c Cone response sigmoidal curve modulating factor :math:`n_c`. Returns ------- :class:`numpy.ndarray` *CIE XYZ* tristimulus values. Raises ------ ValueError If neither *C* or *M* correlates have been defined in the ``CAM_Specification_Kim2009`` argument. Notes ----- +---------------------------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +=================================+=======================+===============+ | ``CAM_Specification_Kim2009.J`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.C`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.h`` | [0, 360] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.s`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.Q`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.M`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``CAM_Specification_Kim2009.H`` | [0, 360] | [0, 1] | +---------------------------------+-----------------------+---------------+ | ``XYZ_w`` | [0, 100] | [0, 1] | +---------------------------------+-----------------------+---------------+ +-----------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +===========+=======================+===============+ | ``XYZ`` | [0, 100] | [0, 1] | +-----------+-----------------------+---------------+ References ---------- :cite:`Kim2009` Examples -------- >>> specification = CAM_Specification_Kim2009(J=28.861908975839647, ... C=0.5592455924373706, ... h=219.04806677662953) >>> XYZ_w = np.array([95.05, 100.00, 108.88]) >>> L_A = 318.31 >>> media = MEDIA_PARAMETERS_KIM2009['CRT Displays'] >>> surround = VIEWING_CONDITIONS_KIM2009['Average'] >>> Kim2009_to_XYZ(specification, XYZ_w, L_A, media, surround) ... # doctest: +ELLIPSIS array([ 19.0099995..., 19.9999999..., 21.7800000...]) """ J, C, h, _s, _Q, M, _H, _HC = astuple(specification) J = to_domain_100(J) C = to_domain_100(C) h = to_domain_degrees(h) M = to_domain_100(M) L_A = as_float_array(L_A) XYZ_w = to_domain_100(XYZ_w) _X_w, Y_w, _Z_w = tsplit(XYZ_w) # Converting *CIE XYZ* tristimulus values to *CMCCAT2000* transform # sharpened *RGB* values. RGB_w = vector_dot(CAT_CAT02, XYZ_w) # Computing degree of adaptation :math:`D`. D = ( degree_of_adaptation(surround.F, L_A) if not discount_illuminant else ones(L_A.shape) ) # Computing full chromatic adaptation. XYZ_wc = full_chromatic_adaptation_forward(RGB_w, RGB_w, Y_w, D) # Converting to *Hunt-Pointer-Estevez* colourspace. LMS_w = RGB_to_rgb(XYZ_wc) # n_q = 0.1308 # J = Q / spow(Y_w, n_q) if has_only_nan(C) and not has_only_nan(M): a_m, b_m = 0.11, 0.61 C = M / (a_m * np.log10(Y_w) + b_m) elif has_only_nan(C): raise ValueError( 'Either "C" or "M" correlate must be defined in ' 'the "CAM_Specification_Kim2009" argument!' ) # Cones absolute response. LMS_w_n_c = spow(LMS_w, n_c) L_A_n_c = spow(L_A, n_c) LMS_wp = LMS_w_n_c / (LMS_w_n_c + L_A_n_c) # Achromatic signal :math:`A_w` v_A = np.array([40, 20, 1]) A_w = np.sum(v_A * LMS_wp, axis=-1) / 61 # Perceived *Lightness* :math:`J_p`. J_p = (J / 100 - 1) / media.E + 1 # Achromatic signal :math:`A`. a_j, b_j, n_j, o_j = 0.89, 0.24, 3.65, 0.65 J_p_n_j = spow(J_p, n_j) A = A_w * ((a_j * J_p_n_j) / (J_p_n_j + spow(o_j, n_j)) + b_j) # Opponent signals :math:`a` and :math:`b`. a_k, n_k = 456.5, 0.62 C_a_k_n_k = spow(C / a_k, 1 / n_k) hr = np.radians(h) a, b = np.cos(hr) * C_a_k_n_k, np.sin(hr) * C_a_k_n_k # Cones absolute response. M = np.array( [ [1.0000, 0.3215, 0.2053], [1.0000, -0.6351, -0.1860], [1.0000, -0.1568, -4.4904], ] ) LMS_p = vector_dot(M, tstack([A, a, b])) LMS = spow((-spow(L_A, n_c) * LMS_p) / (LMS_p - 1), 1 / n_c) # Converting to *Hunt-Pointer-Estevez* colourspace. RGB_c = rgb_to_RGB(LMS) # Applying inverse full chromatic adaptation. RGB = full_chromatic_adaptation_inverse(RGB_c, RGB_w, Y_w, D) XYZ = vector_dot(CAT_INVERSE_CAT02, RGB) return from_range_100(XYZ)