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

"""
Academy Color Encoding System - Log Encodings
=============================================

Defines the *Academy Color Encoding System* (ACES) log encodings:

-   :func:`colour.models.log_encoding_ACESproxy`
-   :func:`colour.models.log_decoding_ACESproxy`
-   :func:`colour.models.log_encoding_ACEScc`
-   :func:`colour.models.log_decoding_ACEScc`
-   :func:`colour.models.log_encoding_ACEScct`
-   :func:`colour.models.log_decoding_ACEScct`

References
----------
-   :cite:`TheAcademyofMotionPictureArtsandSciences2014q` : The Academy of
    Motion Picture Arts and Sciences, Science and Technology Council, & Academy
    Color Encoding System (ACES) Project Subcommittee. (2014). Technical
    Bulletin TB-2014-004 - Informative Notes on SMPTE ST 2065-1 - Academy Color
    Encoding Specification (ACES) (pp. 1-40). Retrieved December 19, 2014, from
    http://j.mp/TB-2014-004
-   :cite:`TheAcademyofMotionPictureArtsandSciences2014r` : The Academy of
    Motion Picture Arts and Sciences, Science and Technology Council, & Academy
    Color Encoding System (ACES) Project Subcommittee. (2014). Technical
    Bulletin TB-2014-012 - Academy Color Encoding System Version 1.0 Component
    Names (pp. 1-8). Retrieved December 19, 2014, from http://j.mp/TB-2014-012
-   :cite:`TheAcademyofMotionPictureArtsandSciences2014s` : The Academy of
    Motion Picture Arts and Sciences, Science and Technology Council, & Academy
    Color Encoding System (ACES) Project Subcommittee. (2013). Specification
    S-2013-001 - ACESproxy, an int Log Encoding of ACES Image Data.
    Retrieved December 19, 2014, from http://j.mp/S-2013-001
-   :cite:`TheAcademyofMotionPictureArtsandSciences2014t` : The Academy of
    Motion Picture Arts and Sciences, Science and Technology Council, & Academy
    Color Encoding System (ACES) Project Subcommittee. (2014). Specification
    S-2014-003 - ACEScc, A Logarithmic Encoding of ACES Data for use within
    Color Grading Systems (pp. 1-12). Retrieved December 19, 2014, from
    http://j.mp/S-2014-003
-   :cite:`TheAcademyofMotionPictureArtsandSciences2016c` : The Academy of
    Motion Picture Arts and Sciences, Science and Technology Council, & Academy
    Color Encoding System (ACES) Project. (2016). Specification S-2016-001 -
    ACEScct, A Quasi-Logarithmic Encoding of ACES Data for use within Color
    Grading Systems. Retrieved October 10, 2016, from http://j.mp/S-2016-001
-   :cite:`TheAcademyofMotionPictureArtsandSciencese` : The Academy of Motion
    Picture Arts and Sciences, Science and Technology Council, & Academy Color
    Encoding System (ACES) Project Subcommittee. (n.d.). Academy Color Encoding
    System. Retrieved February 24, 2014, from
    http://www.oscars.org/science-technology/council/projects/aces.html
"""

from __future__ import annotations

import numpy as np

from colour.hints import ArrayLike, NDArrayFloat, NDArrayInt, Literal, Union
from colour.utilities import (
    Structure,
    as_float,
    as_int,
    from_range_1,
    to_domain_1,
)

__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__ = [
    "CONSTANTS_ACES_PROXY_10",
    "CONSTANTS_ACES_PROXY_12",
    "CONSTANTS_ACES_PROXY",
    "CONSTANTS_ACES_CCT",
    "log_encoding_ACESproxy",
    "log_decoding_ACESproxy",
    "log_encoding_ACEScc",
    "log_decoding_ACEScc",
    "log_encoding_ACEScct",
    "log_decoding_ACEScct",
]

CONSTANTS_ACES_PROXY_10: Structure = Structure(
    CV_min=64,
    CV_max=940,
    steps_per_stop=50,
    mid_CV_offset=425,
    mid_log_offset=2.5,
)
"""*ACESproxy* 10 bit constants."""

CONSTANTS_ACES_PROXY_12: Structure = Structure(
    CV_min=256,
    CV_max=3760,
    steps_per_stop=200,
    mid_CV_offset=1700,
    mid_log_offset=2.5,
)
"""*ACESproxy* 12 bit constants."""

CONSTANTS_ACES_PROXY: dict = {
    10: CONSTANTS_ACES_PROXY_10,
    12: CONSTANTS_ACES_PROXY_12,
}
"""Aggregated *ACESproxy* constants."""

CONSTANTS_ACES_CCT: Structure = Structure(
    X_BRK=0.0078125,
    Y_BRK=0.155251141552511,
    A=10.5402377416545,
    B=0.0729055341958355,
)
"""*ACEScct* constants."""


# pylint: disable=W0102
[docs]def log_encoding_ACESproxy( lin_AP1: ArrayLike, bit_depth: Literal[10, 12] = 10, out_int: bool = False, constants: dict = CONSTANTS_ACES_PROXY, ) -> Union[NDArrayFloat, NDArrayInt]: """ Define the *ACESproxy* colourspace log encoding curve / opto-electronic transfer function. Parameters ---------- lin_AP1 *lin_AP1* value. bit_depth *ACESproxy* bit-depth. out_in Whether to return value as int code value or float equivalent of a code value at a given bit-depth. constants *ACESproxy* constants. Returns ------- :class:`numpy.ndarray` *ACESproxy* non-linear value. Notes ----- +----------------+-----------------------+---------------+ | **Domain \\*** | **Scale - Reference** | **Scale - 1** | +================+=======================+===============+ | ``lin_AP1`` | [0, 1] | [0, 1] | +----------------+-----------------------+---------------+ +----------------+-----------------------+---------------+ | **Range \\*** | **Scale - Reference** | **Scale - 1** | +================+=======================+===============+ | ``ACESproxy`` | [0, 1] | [0, 1] | +----------------+-----------------------+---------------+ \\* This definition has an output int switch, thus the domain-range scale information is only given for the floating point mode. References ---------- :cite:`TheAcademyofMotionPictureArtsandSciences2014q`, :cite:`TheAcademyofMotionPictureArtsandSciences2014r`, :cite:`TheAcademyofMotionPictureArtsandSciences2014s`, :cite:`TheAcademyofMotionPictureArtsandSciencese` Examples -------- >>> log_encoding_ACESproxy(0.18) # doctest: +ELLIPSIS 0.4164222... >>> log_encoding_ACESproxy(0.18, out_int=True) 426 """ lin_AP1 = to_domain_1(lin_AP1) CV_min = constants[bit_depth].CV_min CV_max = constants[bit_depth].CV_max mid_CV_offset = constants[bit_depth].mid_CV_offset mid_log_offset = constants[bit_depth].mid_log_offset steps_per_stop = constants[bit_depth].steps_per_stop def float_2_cv(x: float) -> float: """Convert given numeric to code value.""" return np.maximum(CV_min, np.minimum(CV_max, np.round(x))) ACESproxy = np.where( lin_AP1 > 2**-9.72, float_2_cv( (np.log2(lin_AP1) + mid_log_offset) * steps_per_stop + mid_CV_offset ), np.resize(CV_min, lin_AP1.shape), ) if out_int: return as_int(np.round(ACESproxy)) else: return as_float(from_range_1(ACESproxy / (2**bit_depth - 1)))
# pylint: disable=W0102
[docs]def log_decoding_ACESproxy( ACESproxy: Union[ArrayLike, ArrayLike], bit_depth: Literal[10, 12] = 10, in_int: bool = False, constants: dict = CONSTANTS_ACES_PROXY, ) -> NDArrayFloat: """ Define the *ACESproxy* colourspace log decoding curve / electro-optical transfer function. Parameters ---------- ACESproxy *ACESproxy* non-linear value. bit_depth *ACESproxy* bit-depth. in_int Whether to treat the input value as int code value or float equivalent of a code value at a given bit-depth. constants *ACESproxy* constants. Returns ------- :class:`numpy.ndarray` *lin_AP1* value. Notes ----- +----------------+-----------------------+---------------+ | **Domain \\*** | **Scale - Reference** | **Scale - 1** | +================+=======================+===============+ | ``ACESproxy`` | [0, 1] | [0, 1] | +----------------+-----------------------+---------------+ +----------------+-----------------------+---------------+ | **Range \\*** | **Scale - Reference** | **Scale - 1** | +================+=======================+===============+ | ``lin_AP1`` | [0, 1] | [0, 1] | +----------------+-----------------------+---------------+ \\* This definition has an input int switch, thus the domain-range scale information is only given for the floating point mode. References ---------- :cite:`TheAcademyofMotionPictureArtsandSciences2014q`, :cite:`TheAcademyofMotionPictureArtsandSciences2014r`, :cite:`TheAcademyofMotionPictureArtsandSciences2014s`, :cite:`TheAcademyofMotionPictureArtsandSciencese` Examples -------- >>> log_decoding_ACESproxy(0.416422287390029) # doctest: +ELLIPSIS 0.1... >>> log_decoding_ACESproxy(426, in_int=True) # doctest: +ELLIPSIS 0.1... """ ACESproxy = to_domain_1(ACESproxy) mid_CV_offset = constants[bit_depth].mid_CV_offset mid_log_offset = constants[bit_depth].mid_log_offset steps_per_stop = constants[bit_depth].steps_per_stop if not in_int: ACESproxy = ACESproxy * (2**bit_depth - 1) lin_AP1 = 2 ** ( (ACESproxy - mid_CV_offset) / steps_per_stop - mid_log_offset ) return as_float(from_range_1(lin_AP1))
[docs]def log_encoding_ACEScc(lin_AP1: ArrayLike) -> NDArrayFloat: """ Define the *ACEScc* colourspace log encoding / opto-electronic transfer function. Parameters ---------- lin_AP1 *lin_AP1* value. Returns ------- :class:`numpy.ndarray` *ACEScc* non-linear value. Notes ----- +-------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``lin_AP1`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ +-------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``ACEScc`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ References ---------- :cite:`TheAcademyofMotionPictureArtsandSciences2014q`, :cite:`TheAcademyofMotionPictureArtsandSciences2014r`, :cite:`TheAcademyofMotionPictureArtsandSciences2014t`, :cite:`TheAcademyofMotionPictureArtsandSciencese` Examples -------- >>> log_encoding_ACEScc(0.18) # doctest: +ELLIPSIS 0.4135884... """ lin_AP1 = to_domain_1(lin_AP1) ACEScc = np.where( lin_AP1 < 0, (np.log2(2**-16) + 9.72) / 17.52, (np.log2(2**-16 + lin_AP1 * 0.5) + 9.72) / 17.52, ) ACEScc = np.where( lin_AP1 >= 2**-15, (np.log2(lin_AP1) + 9.72) / 17.52, ACEScc, ) return as_float(from_range_1(ACEScc))
[docs]def log_decoding_ACEScc(ACEScc: ArrayLike) -> NDArrayFloat: """ Define the *ACEScc* colourspace log decoding / electro-optical transfer function. Parameters ---------- ACEScc *ACEScc* non-linear value. Returns ------- :class:`numpy.ndarray` *lin_AP1* value. Notes ----- +-------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``ACEScc`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ +-------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``lin_AP1`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ References ---------- :cite:`TheAcademyofMotionPictureArtsandSciences2014q`, :cite:`TheAcademyofMotionPictureArtsandSciences2014r`, :cite:`TheAcademyofMotionPictureArtsandSciences2014t`, :cite:`TheAcademyofMotionPictureArtsandSciencese` Examples -------- >>> log_decoding_ACEScc(0.413588402492442) # doctest: +ELLIPSIS 0.1799999... """ ACEScc = to_domain_1(ACEScc) lin_AP1 = np.where( ACEScc < (9.72 - 15) / 17.52, (2 ** (ACEScc * 17.52 - 9.72) - 2**-16) * 2, 2 ** (ACEScc * 17.52 - 9.72), ) lin_AP1 = np.where( ACEScc >= (np.log2(65504) + 9.72) / 17.52, 65504, lin_AP1, ) return as_float(from_range_1(lin_AP1))
# pylint: disable=W0102
[docs]def log_encoding_ACEScct( lin_AP1: ArrayLike, constants: Structure = CONSTANTS_ACES_CCT ) -> NDArrayFloat: """ Define the *ACEScct* colourspace log encoding / opto-electronic transfer function. Parameters ---------- lin_AP1 *lin_AP1* value. constants *ACEScct* constants. Returns ------- :class:`numpy.ndarray` *ACEScct* non-linear value. Notes ----- +-------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``lin_AP1`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ +-------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``ACEScct`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ References ---------- :cite:`TheAcademyofMotionPictureArtsandSciences2014q`, :cite:`TheAcademyofMotionPictureArtsandSciences2014r`, :cite:`TheAcademyofMotionPictureArtsandSciences2016c`, :cite:`TheAcademyofMotionPictureArtsandSciencese` Examples -------- >>> log_encoding_ACEScct(0.18) # doctest: +ELLIPSIS 0.4135884... """ lin_AP1 = to_domain_1(lin_AP1) ACEScct = np.where( lin_AP1 <= constants.X_BRK, constants.A * lin_AP1 + constants.B, (np.log2(lin_AP1) + 9.72) / 17.52, ) return as_float(from_range_1(ACEScct))
# pylint: disable=W0102
[docs]def log_decoding_ACEScct( ACEScct: ArrayLike, constants: Structure = CONSTANTS_ACES_CCT ) -> NDArrayFloat: """ Define the *ACEScct* colourspace log decoding / electro-optical transfer function. Parameters ---------- ACEScct *ACEScct* non-linear value. constants *ACEScct* constants. Returns ------- :class:`numpy.ndarray` *lin_AP1* value. References ---------- :cite:`TheAcademyofMotionPictureArtsandSciences2014q`, :cite:`TheAcademyofMotionPictureArtsandSciences2014r`, :cite:`TheAcademyofMotionPictureArtsandSciences2016c`, :cite:`TheAcademyofMotionPictureArtsandSciencese` Notes ----- +-------------+-----------------------+---------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``ACEScct`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ +-------------+-----------------------+---------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +=============+=======================+===============+ | ``lin_AP1`` | [0, 1] | [0, 1] | +-------------+-----------------------+---------------+ Examples -------- >>> log_decoding_ACEScct(0.413588402492442) # doctest: +ELLIPSIS 0.1799999... """ ACEScct = to_domain_1(ACEScct) lin_AP1 = np.where( ACEScct > constants.Y_BRK, 2 ** (ACEScct * 17.52 - 9.72), (ACEScct - constants.B) / constants.A, ) return as_float(from_range_1(lin_AP1))