"""
Sony Encodings
==============
Defines the *Sony* log encodings:
- :func:`colour.models.log_encoding_SLog`
- :func:`colour.models.log_decoding_SLog`
- :func:`colour.models.log_encoding_SLog2`
- :func:`colour.models.log_decoding_SLog2`
- :func:`colour.models.log_encoding_SLog3`
- :func:`colour.models.log_decoding_SLog3`
References
----------
- :cite:`SonyCorporation2012a` : Sony Corporation. (2012). S-Log2 Technical
Paper (pp. 1-9). https://drive.google.com/file/d/\
1Q1RYri6BaxtYYxX0D4zVD6lAmbwmgikc/view?usp=sharing
- :cite:`SonyCorporationd` : Sony Corporation. (n.d.). Technical Summary
for S-Gamut3.Cine/S-Log3 and S-Gamut3/S-Log3 (pp. 1-7).
http://community.sony.com/sony/attachments/sony/\
large-sensor-camera-F5-F55/12359/2/TechnicalSummary_for_S-Gamut3Cine_S-Gamut3_S-Log3_V1_00.pdf
"""
from __future__ import annotations
import numpy as np
from colour.hints import (
ArrayLike,
NDArrayFloat,
)
from colour.models.rgb.transfer_functions import full_to_legal, legal_to_full
from colour.utilities import (
as_float,
as_float_array,
domain_range_scale,
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_SLog",
"log_decoding_SLog",
"log_encoding_SLog2",
"log_decoding_SLog2",
"log_encoding_SLog3",
"log_decoding_SLog3",
]
[docs]
def log_encoding_SLog(
x: ArrayLike,
bit_depth: int = 10,
out_normalised_code_value: bool = True,
in_reflection: bool = True,
) -> NDArrayFloat:
"""
Define the *Sony S-Log* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
bit_depth
Bit-depth used for conversion.
out_normalised_code_value
Whether the non-linear *Sony S-Log* data :math:`y` is encoded as
normalised code values.
in_reflection
Whether the light level :math:`x` to a camera is reflection.
Returns
-------
:class:`numpy.ndarray`
Non-linear *Sony S-Log* 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:`SonyCorporation2012a`
Examples
--------
>>> log_encoding_SLog(0.18) # doctest: +ELLIPSIS
0.3849708...
The values of *IRE and CV of S-Log2 @ISO800* table in
:cite:`SonyCorporation2012a` are obtained as follows:
>>> x = np.array([0, 18, 90]) / 100
>>> np.around(log_encoding_SLog(x, 10, False) * 100).astype(np.int_)
array([ 3, 38, 65])
>>> np.around(log_encoding_SLog(x) * (2**10 - 1)).astype(np.int_)
array([ 90, 394, 636])
"""
x = to_domain_1(x)
if in_reflection:
x = x / 0.9
y = np.where(
x >= 0,
((0.432699 * np.log10(x + 0.037584) + 0.616596) + 0.03),
x * 5 + 0.030001222851889303,
)
y_cv = full_to_legal(y, bit_depth) if out_normalised_code_value else y
return as_float(from_range_1(y_cv))
[docs]
def log_decoding_SLog(
y: ArrayLike,
bit_depth: int = 10,
in_normalised_code_value: bool = True,
out_reflection: bool = True,
) -> NDArrayFloat:
"""
Define the *Sony S-Log* log decoding curve / electro-optical transfer
function.
Parameters
----------
y
Non-linear *Sony S-Log* data :math:`y`.
bit_depth
Bit-depth used for conversion.
in_normalised_code_value
Whether the non-linear *Sony S-Log* data :math:`y` is encoded as
normalised code values.
out_reflection
Whether the light level :math:`x` to a camera is reflection.
Returns
-------
:class:`numpy.ndarray`
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``y`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
+------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``x`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
References
----------
:cite:`SonyCorporation2012a`
Examples
--------
>>> log_decoding_SLog(0.384970815928670) # doctest: +ELLIPSIS
0.1...
"""
y = to_domain_1(y)
x = legal_to_full(y, bit_depth) if in_normalised_code_value else y
with domain_range_scale("ignore"):
x = np.where(
y >= log_encoding_SLog(0.0, bit_depth, in_normalised_code_value),
10 ** ((x - 0.616596 - 0.03) / 0.432699) - 0.037584,
(x - 0.030001222851889303) / 5.0,
)
if out_reflection:
x = x * 0.9
return as_float(from_range_1(x))
[docs]
def log_encoding_SLog2(
x: ArrayLike,
bit_depth: int = 10,
out_normalised_code_value: bool = True,
in_reflection: bool = True,
) -> NDArrayFloat:
"""
Define the *Sony S-Log2* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
bit_depth
Bit-depth used for conversion.
out_normalised_code_value
Whether the non-linear *Sony S-Log2* data :math:`y` is encoded as
normalised code values.
in_reflection
Whether the light level :math:`x` to a camera is reflection.
Returns
-------
:class:`numpy.ndarray`
Non-linear *Sony S-Log2* 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:`SonyCorporation2012a`
Examples
--------
>>> log_encoding_SLog2(0.18) # doctest: +ELLIPSIS
0.3395325...
The values of *IRE and CV of S-Log2 @ISO800* table in
:cite:`SonyCorporation2012a` are obtained as follows:
>>> x = np.array([0, 18, 90]) / 100
>>> np.around(log_encoding_SLog2(x, 10, False) * 100).astype(np.int_)
array([ 3, 32, 59])
>>> np.around(log_encoding_SLog2(x) * (2**10 - 1)).astype(np.int_)
array([ 90, 347, 582])
"""
x = as_float_array(x)
return log_encoding_SLog(
x * 155 / 219, bit_depth, out_normalised_code_value, in_reflection
)
[docs]
def log_decoding_SLog2(
y: ArrayLike,
bit_depth: int = 10,
in_normalised_code_value: bool = True,
out_reflection: bool = True,
) -> NDArrayFloat:
"""
Define the *Sony S-Log2* log decoding curve / electro-optical transfer
function.
Parameters
----------
y
Non-linear *Sony S-Log2* data :math:`y`.
bit_depth
Bit-depth used for conversion.
in_normalised_code_value
Whether the non-linear *Sony S-Log2* data :math:`y` is encoded as
normalised code values.
out_reflection
Whether the light level :math:`x` to a camera is reflection.
Returns
-------
:class:`numpy.ndarray`
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``y`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
+------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``x`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
References
----------
:cite:`SonyCorporation2012a`
Examples
--------
>>> log_decoding_SLog2(0.339532524633774) # doctest: +ELLIPSIS
0.1...
"""
return (
219
* log_decoding_SLog(y, bit_depth, in_normalised_code_value, out_reflection)
/ 155
)
[docs]
def log_encoding_SLog3(
x: ArrayLike,
bit_depth: int = 10,
out_normalised_code_value: bool = True,
in_reflection: bool = True,
) -> NDArrayFloat:
"""
Define the *Sony S-Log3* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
bit_depth
Bit-depth used for conversion.
out_normalised_code_value
Whether the non-linear *Sony S-Log3* data :math:`y` is encoded as
normalised code values.
in_reflection
Whether the light level :math:`x` to a camera is reflection.
Returns
-------
:class:`numpy.ndarray`
Non-linear *Sony S-Log3* 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:`SonyCorporationd`
Examples
--------
>>> log_encoding_SLog3(0.18) # doctest: +ELLIPSIS
0.4105571...
The values of *S-Log3 10bit code values (18%, 90%)* table in
:cite:`SonyCorporationd` are obtained as follows:
>>> x = np.array([0, 18, 90]) / 100
>>> np.around(log_encoding_SLog3(x, 10, False) * 100).astype(np.int_)
array([ 4, 41, 61])
>>> np.around(log_encoding_SLog3(x) * (2**10 - 1)).astype(np.int_)
array([ 95, 420, 598])
"""
x = to_domain_1(x)
if not in_reflection:
x = x * 0.9
y = np.where(
x >= 0.01125000,
(420 + np.log10((x + 0.01) / (0.18 + 0.01)) * 261.5) / 1023,
(x * (171.2102946929 - 95) / 0.01125000 + 95) / 1023,
)
y_cv = y if out_normalised_code_value else legal_to_full(y, bit_depth)
return as_float(from_range_1(y_cv))
[docs]
def log_decoding_SLog3(
y: ArrayLike,
bit_depth: int = 10,
in_normalised_code_value: bool = True,
out_reflection: bool = True,
) -> NDArrayFloat:
"""
Define the *Sony S-Log3* log decoding curve / electro-optical transfer
function.
Parameters
----------
y
Non-linear *Sony S-Log3* data :math:`y`.
bit_depth
Bit-depth used for conversion.
in_normalised_code_value
Whether the non-linear *Sony S-Log3* data :math:`y` is encoded as
normalised code values.
out_reflection
Whether the light level :math:`x` to a camera is reflection.
Returns
-------
:class:`numpy.ndarray`
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``y`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
+------------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``x`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
References
----------
:cite:`SonyCorporationd`
Examples
--------
>>> log_decoding_SLog3(0.410557184750733) # doctest: +ELLIPSIS
0.1...
"""
y = to_domain_1(y)
y = y if in_normalised_code_value else full_to_legal(y, bit_depth)
x = np.where(
y >= 171.2102946929 / 1023,
((10 ** ((y * 1023 - 420) / 261.5)) * (0.18 + 0.01) - 0.01),
(y * 1023 - 95) * 0.01125000 / (171.2102946929 - 95),
)
if not out_reflection:
x = x / 0.9
return as_float(from_range_1(x))