Source code for colour.models.rgb.transfer_functions.gopro
"""
GoPro Encoding
==============
Defines the *GoPro* *Protune* encoding:
- :func:`colour.models.log_encoding_Protune`
- :func:`colour.models.log_decoding_Protune`
References
----------
- :cite:`GoPro2016a` : GoPro, Duiker, H.-P., & Mansencal, T. (2016).
gopro.py. Retrieved April 12, 2017, from
https://github.com/hpd/OpenColorIO-Configs/blob/master/aces_1.0.3/python/\
aces_ocio/colorspaces/gopro.py
"""
from __future__ import annotations
import numpy as np
from colour.hints import ArrayLike, NDArrayFloat
from colour.utilities import as_float, from_range_1, to_domain_1
__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__ = [
"log_encoding_Protune",
"log_decoding_Protune",
]
[docs]
def log_encoding_Protune(x: ArrayLike) -> NDArrayFloat:
"""
Define the *Protune* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x
Linear data :math:`x`.
Returns
-------
:class:`numpy.ndarray`
Non-linear data :math:`y`.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``x`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
+------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``y`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
References
----------
:cite:`GoPro2016a`
Examples
--------
>>> log_encoding_Protune(0.18) # doctest: +ELLIPSIS
0.6456234...
"""
x = to_domain_1(x)
y = np.log1p(x * 112) / np.log(113)
return as_float(from_range_1(y))
[docs]
def log_decoding_Protune(y: ArrayLike) -> NDArrayFloat:
"""
Define the *Protune* log decoding curve / electro-optical transfer
function.
Parameters
----------
y
Non-linear data :math:`y`.
Returns
-------
:class:`numpy.ndarray`
Linear data :math:`x`.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``y`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
+------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``x`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
References
----------
:cite:`GoPro2016a`
Examples
--------
>>> log_decoding_Protune(0.645623486803636) # doctest: +ELLIPSIS
0.1...
"""
y = to_domain_1(y)
x = (113**y - 1) / 112
return as_float(from_range_1(x))