Source code for colour.models.rgb.transfer_functions.cineon
"""
Kodak Cineon Encoding
=====================
Define the *Kodak Cineon* encoding:
- :func:`colour.models.log_encoding_Cineon`
- :func:`colour.models.log_decoding_Cineon`
References
----------
- :cite:`SonyImageworks2012a` : Sony Imageworks. (2012). make.py. Retrieved
November 27, 2014, from
https://github.com/imageworks/OpenColorIO-Configs/blob/master/\
nuke-default/make.py
"""
from __future__ import annotations
import numpy as np
from colour.hints import ArrayLike, NDArrayFloat
from colour.utilities import (
as_float,
as_float_array,
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_Cineon",
"log_decoding_Cineon",
]
[docs]
def log_encoding_Cineon(
x: ArrayLike,
black_offset: ArrayLike = 10 ** ((95 - 685) / 300),
) -> NDArrayFloat:
"""
Define the *Cineon* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x
Linear data :math:`x`.
black_offset
Black offset.
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:`SonyImageworks2012a`
Examples
--------
>>> log_encoding_Cineon(0.18) # doctest: +ELLIPSIS
0.4573196...
"""
x = to_domain_1(x)
black_offset = as_float_array(black_offset)
y = (685 + 300 * np.log10(x * (1 - black_offset) + black_offset)) / 1023
return as_float(from_range_1(y))
[docs]
def log_decoding_Cineon(
y: ArrayLike,
black_offset: ArrayLike = 10 ** ((95 - 685) / 300),
) -> NDArrayFloat:
"""
Define the *Cineon* log decoding curve / electro-optical transfer
function.
Parameters
----------
y
Non-linear data :math:`y`.
black_offset
Black offset.
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:`SonyImageworks2012a`
Examples
--------
>>> log_decoding_Cineon(0.457319613085418) # doctest: +ELLIPSIS
0.1799999...
"""
y = to_domain_1(y)
black_offset = as_float_array(black_offset)
x = (10 ** ((1023 * y - 685) / 300) - black_offset) / (1 - black_offset)
return as_float(from_range_1(x))
