Source code for colour.models.rgb.transfer_functions.itur_bt_2100

# -*- coding: utf-8 -*-
"""
ITU-R BT.2100
=============

Defines *ITU-R BT.2100* opto-electrical transfer functions (OETF / OECF),
opto-optical transfer functions (OOTF / OOCF) and electro-optical transfer
functions (EOTF / EOCF) and their inverse:

-   :func:`colour.models.oetf_PQ_BT2100`
-   :func:`colour.models.oetf_inverse_PQ_BT2100`
-   :func:`colour.models.eotf_PQ_BT2100`
-   :func:`colour.models.eotf_inverse_PQ_BT2100`
-   :func:`colour.models.ootf_PQ_BT2100`
-   :func:`colour.models.ootf_inverse_PQ_BT2100`
-   :func:`colour.models.oetf_HLG_BT2100`
-   :func:`colour.models.oetf_inverse_HLG_BT2100`
-   :func:`colour.models.eotf_HLG_BT2100_1`
-   :func:`colour.models.eotf_HLG_BT2100_2`
-   :attr:`colour.models.BT2100_HLG_EOTF_METHODS`
-   :func:`colour.models.eotf_HLG_BT2100`
-   :func:`colour.models.eotf_inverse_HLG_BT2100_1`
-   :func:`colour.models.eotf_inverse_HLG_BT2100_2`
-   :attr:`colour.models.BT2100_HLG_EOTF_INVERSE_METHODS`
-   :func:`colour.models.eotf_inverse_HLG_BT2100`
-   :func:`colour.models.ootf_HLG_BT2100`
-   :func:`colour.models.ootf_inverse_HLG_BT2100`
-   :func:`colour.models.ootf_HLG_BT2100_1`
-   :func:`colour.models.ootf_HLG_BT2100_2`
-   :attr:`colour.models.BT2100_HLG_OOTF_METHODS`
-   :func:`colour.models.ootf_HLG_BT2100`
-   :func:`colour.models.ootf_inverse_HLG_BT2100_1`
-   :func:`colour.models.ootf_inverse_HLG_BT2100_2`
-   :attr:`colour.models.BT2100_HLG_OOTF_INVERSE_METHODS`
-   :func:`colour.models.ootf_inverse_HLG_BT2100`

References
----------
-   :cite:`Borer2017a` : Borer, T. (2017). Private Discussion with Mansencal,
    T. and Shaw, N.
-   :cite:`InternationalTelecommunicationUnion2017` : International
    Telecommunication Union. (2017). Recommendation ITU-R BT.2100-1 - Image
    parameter values for high dynamic range television for use in production
    and international programme exchange.
    https://www.itu.int/dms_pubrec/itu-r/rec/bt/\
R-REC-BT.2100-1-201706-I!!PDF-E.pdf
-   :cite:`InternationalTelecommunicationUnion2018` : International
    Telecommunication Union. (2018). Recommendation ITU-R BT.2100-2 - Image
    parameter values for high dynamic range television for use in production
    and international programme exchange.
    https://www.itu.int/dms_pubrec/itu-r/rec/bt/\
R-REC-BT.2100-2-201807-I!!PDF-E.pdf
"""

from __future__ import division, unicode_literals

import numpy as np

from colour.algebra import spow
from colour.models.rgb.transfer_functions import (
    eotf_BT1886, eotf_ST2084, eotf_inverse_BT1886, oetf_ARIBSTDB67, oetf_BT709,
    eotf_inverse_ST2084, oetf_inverse_ARIBSTDB67, oetf_inverse_BT709)
from colour.models.rgb.transfer_functions.arib_std_b67 import (
    ARIBSTDB67_CONSTANTS)
from colour.utilities import (
    CaseInsensitiveMapping, Structure, as_float_array, as_float, filter_kwargs,
    from_range_1, to_domain_1, tsplit, tstack, usage_warning)

__author__ = 'Colour Developers'
__copyright__ = 'Copyright (C) 2013-2020 - 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__ = [
    'oetf_PQ_BT2100', 'oetf_inverse_PQ_BT2100', 'eotf_PQ_BT2100',
    'eotf_inverse_PQ_BT2100', 'ootf_PQ_BT2100', 'ootf_inverse_PQ_BT2100',
    'BT2100_HLG_WEIGHTS', 'BT2100_HLG_CONSTANTS', 'gamma_function_HLG_BT2100',
    'oetf_HLG_BT2100', 'oetf_inverse_HLG_BT2100',
    'black_level_lift_HLG_BT2100', 'eotf_HLG_BT2100_1', 'eotf_HLG_BT2100_2',
    'BT2100_HLG_EOTF_METHODS', 'eotf_HLG_BT2100', 'eotf_inverse_HLG_BT2100_1',
    'eotf_inverse_HLG_BT2100_2', 'BT2100_HLG_EOTF_INVERSE_METHODS',
    'eotf_inverse_HLG_BT2100', 'ootf_HLG_BT2100_1', 'ootf_HLG_BT2100_2',
    'BT2100_HLG_OOTF_METHODS', 'ootf_HLG_BT2100', 'ootf_inverse_HLG_BT2100_1',
    'ootf_inverse_HLG_BT2100_2', 'BT2100_HLG_OOTF_INVERSE_METHODS',
    'ootf_inverse_HLG_BT2100'
]


[docs]def oetf_PQ_BT2100(E): """ Defines *Recommendation ITU-R BT.2100* *Reference PQ* opto-electrical transfer function (OETF / OECF). The OETF maps relative scene linear light into the non-linear *PQ* signal value. Parameters ---------- E : numeric or array_like :math:`E = {R_S, G_S, B_S; Y_S; or I_S}` is the signal determined by scene light and scaled by camera exposure. Returns ------- numeric or ndarray :math:`E'` is the resulting non-linear signal (:math:`R'`, :math:`G'`, :math:`B'`). Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> oetf_PQ_BT2100(0.1) # doctest: +ELLIPSIS 0.7247698... """ return eotf_inverse_ST2084(ootf_PQ_BT2100(E), 10000)
[docs]def oetf_inverse_PQ_BT2100(E_p): """ Defines *Recommendation ITU-R BT.2100* *Reference PQ* inverse opto-electrical transfer function (OETF / OECF). Parameters ---------- E_p : numeric or array_like :math:`E'` is the resulting non-linear signal (:math:`R'`, :math:`G'`, :math:`B'`). Returns ------- numeric or ndarray :math:`E = {R_S, G_S, B_S; Y_S; or I_S}` is the signal determined by scene light and scaled by camera exposure. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> oetf_inverse_PQ_BT2100(0.724769816665726) # doctest: +ELLIPSIS 0.0999999... """ return ootf_inverse_PQ_BT2100(eotf_ST2084(E_p, 10000))
[docs]def eotf_PQ_BT2100(E_p): """ Defines *Recommendation ITU-R BT.2100* *Reference PQ* electro-optical transfer function (EOTF / EOCF). The EOTF maps the non-linear *PQ* signal into display light. Parameters ---------- E_p : numeric or array_like :math:`E'` denotes a non-linear colour value :math:`{R', G', B'}` or :math:`{L', M', S'}` in *PQ* space [0, 1]. Returns ------- numeric or ndarray :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> eotf_PQ_BT2100(0.724769816665726) # doctest: +ELLIPSIS 779.9883608... """ return eotf_ST2084(E_p, 10000)
[docs]def eotf_inverse_PQ_BT2100(F_D): """ Defines *Recommendation ITU-R BT.2100* *Reference PQ* inverse electro-optical transfer function (EOTF / EOCF). Parameters ---------- F_D : numeric or array_like :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. Returns ------- numeric or ndarray :math:`E'` denotes a non-linear colour value :math:`{R', G', B'}` or :math:`{L', M', S'}` in *PQ* space [0, 1]. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> eotf_inverse_PQ_BT2100(779.988360834085370) # doctest: +ELLIPSIS 0.7247698... """ return eotf_inverse_ST2084(F_D, 10000)
[docs]def ootf_PQ_BT2100(E): """ Defines *Recommendation ITU-R BT.2100* *Reference PQ* opto-optical transfer function (OOTF / OOCF). The OOTF maps relative scene linear light to display linear light. Parameters ---------- E : numeric or array_like :math:`E = {R_S, G_S, B_S; Y_S; or I_S}` is the signal determined by scene light and scaled by camera exposure. Returns ------- numeric or ndarray :math:`F_D` is the luminance of a displayed linear component (:math:`R_D`, :math:`G_D`, :math:`B_D`; :math:`Y_D`; or :math:`I_D`). Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> ootf_PQ_BT2100(0.1) # doctest: +ELLIPSIS 779.9883608... """ E = as_float_array(E) return 100 * eotf_BT1886(oetf_BT709(59.5208 * E))
[docs]def ootf_inverse_PQ_BT2100(F_D): """ Defines *Recommendation ITU-R BT.2100* *Reference PQ* inverse opto-optical transfer function (OOTF / OOCF). Parameters ---------- F_D : numeric or array_like :math:`F_D` is the luminance of a displayed linear component (:math:`R_D`, :math:`G_D`, :math:`B_D`; :math:`Y_D`; or :math:`I_D`). Returns ------- numeric or ndarray :math:`E = {R_S, G_S, B_S; Y_S; or I_S}` is the signal determined by scene light and scaled by camera exposure. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> ootf_inverse_PQ_BT2100(779.988360834115840) # doctest: +ELLIPSIS 0.1000000... """ F_D = as_float_array(F_D) return oetf_inverse_BT709(eotf_inverse_BT1886(F_D / 100)) / 59.5208
BT2100_HLG_WEIGHTS = np.array([0.2627, 0.6780, 0.0593]) """ Luminance weights for *Recommendation ITU-R BT.2100* *Reference HLG*. BT2100_HLG_WEIGHTS : ndarray """ BT2100_HLG_CONSTANTS = Structure( a=ARIBSTDB67_CONSTANTS.a, b=1 - 4 * ARIBSTDB67_CONSTANTS.a, c=0.5 - ARIBSTDB67_CONSTANTS.a * np.log(4 * ARIBSTDB67_CONSTANTS.a)) """ *Recommendation ITU-R BT.2100* *Reference HLG* constants expressed in their analytical form in contrast to the *ARIB STD-B67 (Hybrid Log-Gamma)* numerical reference. References ---------- :cite:`InternationalTelecommunicationUnion2017` BT2100_HLG_CONSTANTS : Structure """ def gamma_function_HLG_BT2100(L_W=1000): """ Returns the *Reference HLG* system gamma value for given display nominal peak luminance. Parameters ---------- L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. Returns ------- numeric *Reference HLG* system gamma value. Examples -------- >>> gamma_function_HLG_BT2100() 1.2 >>> gamma_function_HLG_BT2100(2000) # doctest: +ELLIPSIS 1.3264325... >>> gamma_function_HLG_BT2100(4000) # doctest: +ELLIPSIS 1.4528651... """ gamma = 1.2 + 0.42 * np.log10(L_W / 1000) return gamma
[docs]def oetf_HLG_BT2100(E, constants=BT2100_HLG_CONSTANTS): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* opto-electrical transfer function (OETF / OECF). The OETF maps relative scene linear light into the non-linear *HLG* signal value. Parameters ---------- E : numeric or array_like :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. Returns ------- numeric or ndarray :math:`E'` is the resulting non-linear signal :math:`{R', G', B'}`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> oetf_HLG_BT2100(0.18 / 12) # doctest: +ELLIPSIS 0.2121320... """ return oetf_ARIBSTDB67(12 * E, constants=constants)
[docs]def oetf_inverse_HLG_BT2100(E_p, constants=BT2100_HLG_CONSTANTS): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse opto-electrical transfer function (OETF / OECF). Parameters ---------- E_p : numeric or array_like :math:`E'` is the resulting non-linear signal :math:`{R', G', B'}`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. Returns ------- numeric or ndarray :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> oetf_inverse_HLG_BT2100(0.212132034355964) # doctest: +ELLIPSIS 0.0149999... """ return oetf_inverse_ARIBSTDB67(E_p, constants=constants) / 12
def black_level_lift_HLG_BT2100(L_B=0, L_W=1000, gamma=None): """ Returns the *Reference HLG* black level lift :math:`\\Beta` for given display luminance for black, nominal peak luminance and system gamma value. Parameters ---------- L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. Returns ------- numeric *Reference HLG* black level lift :math:`\\Beta`. Examples -------- >>> black_level_lift_HLG_BT2100() 0.0 >>> black_level_lift_HLG_BT2100(0.01) # doctest: +ELLIPSIS 0.0142964... >>> black_level_lift_HLG_BT2100(0.001, 2000) # doctest: +ELLIPSIS 0.0073009... >>> black_level_lift_HLG_BT2100(0.01, gamma=1.4) # doctest: +ELLIPSIS 0.0283691... """ if gamma is None: gamma = gamma_function_HLG_BT2100(L_W) beta = np.sqrt(3 * spow((L_B / L_W), 1 / gamma)) return beta def eotf_HLG_BT2100_1(E_p, L_B=0, L_W=1000, gamma=None, constants=BT2100_HLG_CONSTANTS): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* electro-optical transfer function (EOTF / EOCF) as given in *ITU-R BT.2100-1*. The EOTF maps the non-linear *HLG* signal into display light. Parameters ---------- E_p : numeric or array_like :math:`E'` is the non-linear signal :math:`{R', G', B'}` as defined for the OETF. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. Returns ------- numeric or ndarray Luminance :math:`F_D` of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> eotf_HLG_BT2100_1(0.212132034355964) # doctest: +ELLIPSIS 6.4760398... >>> eotf_HLG_BT2100_1(0.212132034355964, 0.01) # doctest: +ELLIPSIS 6.4859750... """ return ootf_HLG_BT2100_1( oetf_inverse_ARIBSTDB67(E_p, constants=constants) / 12, L_B, L_W, gamma) def eotf_HLG_BT2100_2(E_p, L_B=0, L_W=1000, gamma=None, constants=BT2100_HLG_CONSTANTS): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* electro-optical transfer function (EOTF / EOCF) as given in *ITU-R BT.2100-2* with the modified black level behaviour. The EOTF maps the non-linear *HLG* signal into display light. Parameters ---------- E_p : numeric or array_like :math:`E'` is the non-linear signal :math:`{R', G', B'}` as defined for the *HLG Reference* OETF. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. Returns ------- numeric or ndarray Luminance :math:`F_D` of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> eotf_HLG_BT2100_2(0.212132034355964) # doctest: +ELLIPSIS 6.4760398... >>> eotf_HLG_BT2100_2(0.212132034355964, 0.01) # doctest: +ELLIPSIS 7.3321975... """ beta = black_level_lift_HLG_BT2100(L_B, L_W, gamma) return ootf_HLG_BT2100_2( oetf_inverse_ARIBSTDB67( (1 - beta) * E_p + beta, constants=constants) / 12, L_W, gamma) BT2100_HLG_EOTF_METHODS = CaseInsensitiveMapping({ 'ITU-R BT.2100-1': eotf_HLG_BT2100_1, 'ITU-R BT.2100-2': eotf_HLG_BT2100_2, }) BT2100_HLG_EOTF_METHODS.__doc__ = """ Supported *Recommendation ITU-R BT.2100* *Reference HLG* electro-optical transfer function (EOTF / EOCF). References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` BT2100_HLG_EOTF_METHODS : CaseInsensitiveMapping **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}** """
[docs]def eotf_HLG_BT2100(E_p, L_B=0, L_W=1000, gamma=None, constants=BT2100_HLG_CONSTANTS, method='ITU-R BT.2100-2'): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* electro-optical transfer function (EOTF / EOCF). The EOTF maps the non-linear *HLG* signal into display light. Parameters ---------- E_p : numeric or array_like :math:`E'` denotes a non-linear colour value :math:`{R', G', B'}` or :math:`{L', M', S'}` in *HLG* space. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. method : unicode, optional **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}**, Computation method. Returns ------- numeric or ndarray Luminance :math:`F_D` of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> eotf_HLG_BT2100(0.212132034355964) # doctest: +ELLIPSIS 6.4760398... >>> eotf_HLG_BT2100(0.212132034355964, method='ITU-R BT.2100-1') ... # doctest: +ELLIPSIS 6.4760398... >>> eotf_HLG_BT2100(0.212132034355964, 0.01) ... # doctest: +ELLIPSIS 7.3321975... """ return BT2100_HLG_EOTF_METHODS[method](E_p, L_B, L_W, gamma, constants)
def eotf_inverse_HLG_BT2100_1(F_D, L_B=0, L_W=1000, gamma=None, constants=BT2100_HLG_CONSTANTS): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse electro-optical transfer function (EOTF / EOCF) as given in *ITU-R BT.2100-1*. Parameters ---------- F_D : numeric or array_like Luminance :math:`F_D` of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. Returns ------- numeric or ndarray :math:`E'` denotes a non-linear colour value :math:`{R', G', B'}` or :math:`{L', M', S'}` in *HLG* space. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> eotf_inverse_HLG_BT2100_1(6.476039825649814) # doctest: +ELLIPSIS 0.2121320... >>> eotf_inverse_HLG_BT2100_1(6.485975065251558, 0.01) ... # doctest: +ELLIPSIS 0.2121320... """ return oetf_ARIBSTDB67( ootf_inverse_HLG_BT2100_1(F_D, L_B, L_W, gamma) * 12, constants=constants) def eotf_inverse_HLG_BT2100_2(F_D, L_B=0, L_W=1000, gamma=None, constants=BT2100_HLG_CONSTANTS): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse electro-optical transfer function (EOTF / EOCF) as given in *ITU-R BT.2100-2* with the modified black level behaviour. Parameters ---------- F_D : numeric or array_like Luminance :math:`F_D` of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. Returns ------- numeric or ndarray :math:`E'` denotes a non-linear colour value :math:`{R', G', B'}` or :math:`{L', M', S'}` in *HLG* space. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> eotf_inverse_HLG_BT2100_2(6.476039825649814) # doctest: +ELLIPSIS 0.2121320... >>> eotf_inverse_HLG_BT2100_2(7.332197528353875, 0.01) ... # doctest: +ELLIPSIS 0.2121320... """ beta = black_level_lift_HLG_BT2100(L_B, L_W, gamma) return (oetf_ARIBSTDB67( ootf_inverse_HLG_BT2100_2(F_D, L_W, gamma) * 12, constants=constants) - beta) / (1 - beta) BT2100_HLG_EOTF_INVERSE_METHODS = CaseInsensitiveMapping({ 'ITU-R BT.2100-1': eotf_inverse_HLG_BT2100_1, 'ITU-R BT.2100-2': eotf_inverse_HLG_BT2100_2, }) BT2100_HLG_EOTF_INVERSE_METHODS.__doc__ = """ Supported *Recommendation ITU-R BT.2100* *Reference HLG* inverse electro-optical transfer function (EOTF / EOCF). References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` BT2100_HLG_EOTF_INVERSE_METHODS : CaseInsensitiveMapping **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}** """
[docs]def eotf_inverse_HLG_BT2100(F_D, L_B=0, L_W=1000, gamma=None, constants=BT2100_HLG_CONSTANTS, method='ITU-R BT.2100-2'): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse electro-optical transfer function (EOTF / EOCF). Parameters ---------- F_D : numeric or array_like Luminance :math:`F_D` of a displayed linear component :math:`{R_D, G_D, B_D}` or :math:`Y_D` or :math:`I_D`, in :math:`cd/m^2`. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. constants : Structure, optional *Recommendation ITU-R BT.2100* *Reference HLG* constants. method : unicode, optional **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}**, Computation method. Returns ------- numeric or ndarray :math:`E'` denotes a non-linear colour value :math:`{R', G', B'}` or :math:`{L', M', S'}` in *HLG* space. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E_p`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> eotf_inverse_HLG_BT2100(6.476039825649814) # doctest: +ELLIPSIS 0.2121320... >>> eotf_inverse_HLG_BT2100(6.476039825649814, method='ITU-R BT.2100-1') ... # doctest: +ELLIPSIS 0.2121320... >>> eotf_inverse_HLG_BT2100(7.332197528353875, 0.01) # doctest: +ELLIPSIS 0.2121320... """ return BT2100_HLG_EOTF_INVERSE_METHODS[method](F_D, L_B, L_W, gamma, constants)
def ootf_HLG_BT2100_1(E, L_B=0, L_W=1000, gamma=None): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* opto-optical transfer function (OOTF / OOCF) as given in *ITU-R BT.2100-1*. The OOTF maps relative scene linear light to display linear light. Parameters ---------- E : numeric or array_like :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. Returns ------- numeric or ndarray :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, or B_D}`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> ootf_HLG_BT2100_1(0.1) # doctest: +ELLIPSIS 63.0957344... >>> ootf_HLG_BT2100_1(0.1, 0.01) ... # doctest: +ELLIPSIS 63.1051034... """ E = np.atleast_1d(to_domain_1(E)) if E.shape[-1] != 3: usage_warning( '"Recommendation ITU-R BT.2100" "Reference HLG OOTF" uses ' 'RGB Luminance in computations and expects a vector input, thus ' 'the given input array will be stacked to compose a vector for ' 'internal computations but a single component will be output.') R_S = G_S = B_S = E else: R_S, G_S, B_S = tsplit(E) alpha = L_W - L_B beta = L_B Y_S = np.sum(BT2100_HLG_WEIGHTS * tstack([R_S, G_S, B_S]), axis=-1) if gamma is None: gamma = gamma_function_HLG_BT2100(L_W) R_D = alpha * R_S * np.abs(Y_S) ** (gamma - 1) + beta G_D = alpha * G_S * np.abs(Y_S) ** (gamma - 1) + beta B_D = alpha * B_S * np.abs(Y_S) ** (gamma - 1) + beta if E.shape[-1] != 3: return as_float(from_range_1(R_D)) else: RGB_D = tstack([R_D, G_D, B_D]) return from_range_1(RGB_D) def ootf_HLG_BT2100_2(E, L_W=1000, gamma=None): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* opto-optical transfer function (OOTF / OOCF) as given in *ITU-R BT.2100-2*. The OOTF maps relative scene linear light to display linear light. Parameters ---------- E : numeric or array_like :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. Returns ------- numeric or ndarray :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, or B_D}`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> ootf_HLG_BT2100_2(0.1) # doctest: +ELLIPSIS 63.0957344... """ E = np.atleast_1d(to_domain_1(E)) if E.shape[-1] != 3: usage_warning( '"Recommendation ITU-R BT.2100" "Reference HLG OOTF" uses ' 'RGB Luminance in computations and expects a vector input, thus ' 'the given input array will be stacked to compose a vector for ' 'internal computations but a single component will be output.') R_S = G_S = B_S = E else: R_S, G_S, B_S = tsplit(E) alpha = L_W Y_S = np.sum(BT2100_HLG_WEIGHTS * tstack([R_S, G_S, B_S]), axis=-1) if gamma is None: gamma = gamma_function_HLG_BT2100(L_W) R_D = alpha * R_S * np.abs(Y_S) ** (gamma - 1) G_D = alpha * G_S * np.abs(Y_S) ** (gamma - 1) B_D = alpha * B_S * np.abs(Y_S) ** (gamma - 1) if E.shape[-1] != 3: return as_float(from_range_1(R_D)) else: RGB_D = tstack([R_D, G_D, B_D]) return from_range_1(RGB_D) BT2100_HLG_OOTF_METHODS = CaseInsensitiveMapping({ 'ITU-R BT.2100-1': ootf_HLG_BT2100_1, 'ITU-R BT.2100-2': ootf_HLG_BT2100_2, }) BT2100_HLG_OOTF_METHODS.__doc__ = """ Supported *Recommendation ITU-R BT.2100* *Reference HLG* opto-optical transfer function (OOTF / OOCF). References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` BT2100_HLG_OOTF_METHODS : CaseInsensitiveMapping **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}** """
[docs]def ootf_HLG_BT2100(E, L_B=0, L_W=1000, gamma=None, method='ITU-R BT.2100-2'): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* opto-optical transfer function (OOTF / OOCF). The OOTF maps relative scene linear light to display linear light. Parameters ---------- E : numeric or array_like :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. method : unicode, optional **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}**, Computation method. Returns ------- numeric or ndarray :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, or B_D}`, in :math:`cd/m^2`. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> ootf_HLG_BT2100(0.1) # doctest: +ELLIPSIS 63.0957344... >>> ootf_HLG_BT2100(0.1, 0.01, method='ITU-R BT.2100-1') ... # doctest: +ELLIPSIS 63.1051034... """ function = BT2100_HLG_OOTF_METHODS[method] return function( E, **filter_kwargs(function, **{ 'L_B': L_B, 'L_W': L_W, 'gamma': gamma }))
def ootf_inverse_HLG_BT2100_1(F_D, L_B=0, L_W=1000, gamma=None): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse opto-optical transfer function (OOTF / OOCF) as given in *ITU-R BT.2100-1*. Parameters ---------- F_D : numeric or array_like :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, or B_D}`, in :math:`cd/m^2`. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. Returns ------- numeric or ndarray :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017` Examples -------- >>> ootf_inverse_HLG_BT2100_1(63.095734448019336) # doctest: +ELLIPSIS 0.1000000... >>> ootf_inverse_HLG_BT2100_1(63.105103490674857, 0.01) ... # doctest: +ELLIPSIS 0.0999999... """ F_D = np.atleast_1d(to_domain_1(F_D)) if F_D.shape[-1] != 3: usage_warning( '"Recommendation ITU-R BT.2100" "Reference HLG OOTF" uses ' 'RGB Luminance in computations and expects a vector input, thus ' 'the given input array will be stacked to compose a vector for ' 'internal computations but a single component will be output.') R_D = G_D = B_D = F_D else: R_D, G_D, B_D = tsplit(F_D) Y_D = np.sum(BT2100_HLG_WEIGHTS * tstack([R_D, G_D, B_D]), axis=-1) alpha = L_W - L_B beta = L_B if gamma is None: gamma = gamma_function_HLG_BT2100(L_W) Y_D_beta = (np.abs((Y_D - beta) / alpha) ** ((1 - gamma) / gamma)) R_S = np.where( Y_D == beta, 0.0, Y_D_beta * (R_D - beta) / alpha, ) G_S = np.where( Y_D == beta, 0.0, Y_D_beta * (G_D - beta) / alpha, ) B_S = np.where( Y_D == beta, 0.0, Y_D_beta * (B_D - beta) / alpha, ) if F_D.shape[-1] != 3: return as_float(from_range_1(R_S)) else: RGB_S = tstack([R_S, G_S, B_S]) return from_range_1(RGB_S) def ootf_inverse_HLG_BT2100_2(F_D, L_W=1000, gamma=None): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse opto-optical transfer function (OOTF / OOCF) as given in *ITU-R BT.2100-2*. Parameters ---------- F_D : numeric or array_like :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, or B_D}`, in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. Returns ------- numeric or ndarray :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> ootf_inverse_HLG_BT2100_2(63.095734448019336) # doctest: +ELLIPSIS 0.1000000... """ F_D = np.atleast_1d(to_domain_1(F_D)) if F_D.shape[-1] != 3: usage_warning( '"Recommendation ITU-R BT.2100" "Reference HLG OOTF" uses ' 'RGB Luminance in computations and expects a vector input, thus ' 'the given input array will be stacked to compose a vector for ' 'internal computations but a single component will be output.') R_D = G_D = B_D = F_D else: R_D, G_D, B_D = tsplit(F_D) Y_D = np.sum(BT2100_HLG_WEIGHTS * tstack([R_D, G_D, B_D]), axis=-1) alpha = L_W if gamma is None: gamma = gamma_function_HLG_BT2100(L_W) Y_D_alpha = (np.abs(Y_D / alpha) ** ((1 - gamma) / gamma)) R_S = np.where( Y_D == 0, 0.0, Y_D_alpha * R_D / alpha, ) G_S = np.where( Y_D == 0, 0.0, Y_D_alpha * G_D / alpha, ) B_S = np.where( Y_D == 0, 0.0, Y_D_alpha * B_D / alpha, ) if F_D.shape[-1] != 3: return as_float(from_range_1(R_S)) else: RGB_S = tstack([R_S, G_S, B_S]) return from_range_1(RGB_S) BT2100_HLG_OOTF_INVERSE_METHODS = CaseInsensitiveMapping({ 'ITU-R BT.2100-1': ootf_inverse_HLG_BT2100_1, 'ITU-R BT.2100-2': ootf_inverse_HLG_BT2100_2, }) BT2100_HLG_OOTF_INVERSE_METHODS.__doc__ = """ Supported *Recommendation ITU-R BT.2100* *Reference HLG* inverse opto-optical transfer function (OOTF / OOCF). References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` BT2100_HLG_OOTF_INVERSE_METHODS : CaseInsensitiveMapping **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}** """
[docs]def ootf_inverse_HLG_BT2100(F_D, L_B=0, L_W=1000, gamma=None, method='ITU-R BT.2100-2'): """ Defines *Recommendation ITU-R BT.2100* *Reference HLG* inverse opto-optical transfer function (OOTF / OOCF). Parameters ---------- F_D : numeric or array_like :math:`F_D` is the luminance of a displayed linear component :math:`{R_D, G_D, or B_D}`, in :math:`cd/m^2`. L_B : numeric, optional :math:`L_B` is the display luminance for black in :math:`cd/m^2`. L_W : numeric, optional :math:`L_W` is nominal peak luminance of the display in :math:`cd/m^2` for achromatic pixels. gamma : numeric, optional System gamma value, 1.2 at the nominal display peak luminance of :math:`1000 cd/m^2`. method : unicode, optional **{'ITU-R BT.2100-1', 'ITU-R BT.2100-2'}**, Computation method. Returns ------- numeric or ndarray :math:`E` is the signal for each colour component :math:`{R_S, G_S, B_S}` proportional to scene linear light and scaled by camera exposure. Notes ----- +------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``F_D`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ +------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+=======================+===============+ | ``E`` | [0, 1] | [0, 1] | +------------+-----------------------+---------------+ References ---------- :cite:`Borer2017a`, :cite:`InternationalTelecommunicationUnion2017`, :cite:`InternationalTelecommunicationUnion2018` Examples -------- >>> ootf_inverse_HLG_BT2100(63.095734448019336) # doctest: +ELLIPSIS 0.1000000... >>> ootf_inverse_HLG_BT2100( ... 63.105103490674857, 0.01, method='ITU-R BT.2100-1') ... # doctest: +ELLIPSIS 0.0999999... """ function = BT2100_HLG_OOTF_INVERSE_METHODS[method] return function( F_D, **filter_kwargs(function, **{ 'L_B': L_B, 'L_W': L_W, 'gamma': gamma }))