# -*- coding: utf-8 -*-
"""
Sony S-Log Encodings
====================
Defines the *Sony S-Log* 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`
See Also
--------
`RGB Colourspaces Jupyter Notebook
<http://nbviewer.jupyter.org/github/colour-science/colour-notebooks/\
blob/master/notebooks/models/rgb.ipynb>`_
References
----------
- :cite:`SonyCorporation2012a` : Sony Corporation. (2012). S-Log2 Technical
Paper. Retrieved from https://pro.sony.com/bbsccms/assets/files/micro/\
dmpc/training/S-Log2_Technical_PaperV1_0.pdf
- :cite:`SonyCorporationd` : Sony Corporation. (n.d.). Technical Summary for
S-Gamut3.Cine/S-Log3 and S-Gamut3/S-Log3. Retrieved from
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 division, unicode_literals
import numpy as np
from colour.models.rgb.transfer_functions import full_to_legal, legal_to_full
from colour.utilities import (as_float, domain_range_scale, from_range_1,
to_domain_1)
from colour.utilities.deprecation import handle_arguments_deprecation
__author__ = 'Colour Developers'
__copyright__ = 'Copyright (C) 2013-2019 - Colour Developers'
__license__ = 'New BSD License - https://opensource.org/licenses/BSD-3-Clause'
__maintainer__ = 'Colour Developers'
__email__ = 'colour-science@googlegroups.com'
__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,
bit_depth=10,
out_normalised_code_value=True,
in_reflection=True,
**kwargs):
"""
Defines the *Sony S-Log* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x : numeric or array_like
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
bit_depth : int, optional
Bit depth used for conversion.
out_normalised_code_value : bool, optional
Whether the non-linear *Sony S-Log* data :math:`y` is encoded as
normalised code values.
in_reflection : bool, optional
Whether the light level :math:`x` to a camera is reflection.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
numeric or 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])
"""
out_normalised_code_value = handle_arguments_deprecation({
'ArgumentRenamed': [['out_legal', 'out_normalised_code_value']],
}, **kwargs).get('out_normalised_code_value', out_normalised_code_value)
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 = full_to_legal(y, bit_depth) if out_normalised_code_value else y
return as_float(from_range_1(y))
[docs]def log_decoding_SLog(y,
bit_depth=10,
in_normalised_code_value=True,
out_reflection=True,
**kwargs):
"""
Defines the *Sony S-Log* log decoding curve / electro-optical transfer
function.
Parameters
----------
y : numeric or array_like
Non-linear *Sony S-Log* data :math:`y`.
bit_depth : int, optional
Bit depth used for conversion.
in_normalised_code_value : bool, optional
Whether the non-linear *Sony S-Log* data :math:`y` is encoded as
normalised code values.
out_reflection : bool, optional
Whether the light level :math:`x` to a camera is reflection.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
numeric or 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...
"""
in_normalised_code_value = handle_arguments_deprecation({
'ArgumentRenamed': [['in_legal', 'in_normalised_code_value']],
}, **kwargs).get('in_normalised_code_value', in_normalised_code_value)
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,
bit_depth=10,
out_normalised_code_value=True,
in_reflection=True,
**kwargs):
"""
Defines the *Sony S-Log2* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x : numeric or array_like
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
bit_depth : int, optional
Bit depth used for conversion.
out_normalised_code_value : bool, optional
Whether the non-linear *Sony S-Log2* data :math:`y` is encoded as
normalised code values.
in_reflection : bool, optional
Whether the light level :math:`x` to a camera is reflection.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
numeric or 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])
"""
out_normalised_code_value = handle_arguments_deprecation({
'ArgumentRenamed': [['out_legal', 'out_normalised_code_value']],
}, **kwargs).get('out_normalised_code_value', out_normalised_code_value)
return log_encoding_SLog(x * 155 / 219, bit_depth,
out_normalised_code_value, in_reflection)
[docs]def log_decoding_SLog2(y,
bit_depth=10,
in_normalised_code_value=True,
out_reflection=True,
**kwargs):
"""
Defines the *Sony S-Log2* log decoding curve / electro-optical transfer
function.
Parameters
----------
y : numeric or array_like
Non-linear *Sony S-Log2* data :math:`y`.
bit_depth : int, optional
Bit depth used for conversion.
in_normalised_code_value : bool, optional
Whether the non-linear *Sony S-Log2* data :math:`y` is encoded as
normalised code values.
out_reflection : bool, optional
Whether the light level :math:`x` to a camera is reflection.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
numeric or 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...
"""
in_normalised_code_value = handle_arguments_deprecation({
'ArgumentRenamed': [['in_legal', 'in_normalised_code_value']],
}, **kwargs).get('in_normalised_code_value', in_normalised_code_value)
return 219 * log_decoding_SLog(y, bit_depth, in_normalised_code_value,
out_reflection) / 155
[docs]def log_encoding_SLog3(x,
bit_depth=10,
out_normalised_code_value=True,
in_reflection=True,
**kwargs):
"""
Defines the *Sony S-Log3* log encoding curve / opto-electronic transfer
function.
Parameters
----------
x : numeric or array_like
Reflection or :math:`IRE / 100` input light level :math:`x` to a
camera.
bit_depth : int, optional
Bit depth used for conversion.
out_normalised_code_value : bool, optional
Whether the non-linear *Sony S-Log3* data :math:`y` is encoded as
normalised code values.
in_reflection : bool, optional
Whether the light level :math:`x` to a camera is reflection.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
numeric or 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])
"""
out_normalised_code_value = handle_arguments_deprecation({
'ArgumentRenamed': [['out_legal', 'out_normalised_code_value']],
}, **kwargs).get('out_normalised_code_value', out_normalised_code_value)
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 = y if out_normalised_code_value else legal_to_full(y, bit_depth)
return as_float(from_range_1(y))
[docs]def log_decoding_SLog3(y,
bit_depth=10,
in_normalised_code_value=True,
out_reflection=True,
**kwargs):
"""
Defines the *Sony S-Log3* log decoding curve / electro-optical transfer
function.
Parameters
----------
y : numeric or array_like
Non-linear *Sony S-Log3* data :math:`y`.
bit_depth : int, optional
Bit depth used for conversion.
in_normalised_code_value : bool, optional
Whether the non-linear *Sony S-Log3* data :math:`y` is encoded as
normalised code values.
out_reflection : bool, optional
Whether the light level :math:`x` to a camera is reflection.
Other Parameters
----------------
\\**kwargs : dict, optional
Keywords arguments for deprecation management.
Returns
-------
numeric or 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...
"""
in_normalised_code_value = handle_arguments_deprecation({
'ArgumentRenamed': [['in_legal', 'in_normalised_code_value']],
}, **kwargs).get('in_normalised_code_value', in_normalised_code_value)
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))