#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Sony S-Gamut Colourspace
========================
Defines the *S-Gamut*, *S-Gamut3* and *S-Gamut3.Cine* colourspaces:
- :attr:`S_GAMUT_COLOURSPACE`.
- :attr:`S_GAMUT3_COLOURSPACE`.
- :attr:`S_GAMUT3_CINE_COLOURSPACE`.
See Also
--------
`RGB Colourspaces IPython Notebook
<http://nbviewer.ipython.org/github/colour-science/colour-ipython/blob/master/notebooks/models/rgb.ipynb>`_ # noqa
References
----------
.. [1] Gaggioni, H., Dhanendra, P., Yamashita, J., Kawada, N., Endo, K., &
Clark, C. (n.d.). S-Log: A new LUT for digital production mastering
and interchange applications. Retrieved from
http://pro.sony.com/bbsccms/assets/files/mkt/cinema/solutions/slog_manual.pdf # noqa
.. [2] Sony Corporation. (n.d.). S-Log Whitepaper. Retrieved from
http://www.theodoropoulos.info/attachments/076_on S-Log.pdf
.. [3] 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 # noqa
"""
from __future__ import division, unicode_literals
import numpy as np
from colour.colorimetry import ILLUMINANTS
from colour.models import RGB_Colourspace, normalised_primary_matrix
__author__ = 'Colour Developers'
__copyright__ = 'Copyright (C) 2013 - 2015 - Colour Developers'
__license__ = 'New BSD License - http://opensource.org/licenses/BSD-3-Clause'
__maintainer__ = 'Colour Developers'
__email__ = 'colour-science@googlegroups.com'
__status__ = 'Production'
__all__ = ['S_GAMUT_PRIMARIES',
'S_GAMUT_ILLUMINANT',
'S_GAMUT_WHITEPOINT',
'S_GAMUT_TO_XYZ_MATRIX',
'XYZ_TO_S_GAMUT_MATRIX',
'S_LOG_TRANSFER_FUNCTION',
'S_LOG_INVERSE_TRANSFER_FUNCTION',
'S_LOG2_TRANSFER_FUNCTION',
'S_LOG2_INVERSE_TRANSFER_FUNCTION',
'S_GAMUT_COLOURSPACE',
'S_LOG3_TRANSFER_FUNCTION',
'S_LOG3_INVERSE_TRANSFER_FUNCTION',
'S_GAMUT3_COLOURSPACE',
'S_GAMUT3_CINE_PRIMARIES',
'S_GAMUT3_CINE_ILLUMINANT',
'S_GAMUT3_CINE_WHITEPOINT',
'S_GAMUT3_CINE_TO_XYZ_MATRIX',
'XYZ_TO_S_GAMUT3_CINE_MATRIX',
'S_GAMUT3_CINE_COLOURSPACE']
S_GAMUT_PRIMARIES = np.array(
[[0.73, 0.28],
[0.14, 0.855],
[0.10, -0.05]])
"""
*S-Gamut* colourspace primaries.
S_GAMUT_PRIMARIES : ndarray, (3, 2)
"""
S_GAMUT_ILLUMINANT = 'D65'
"""
*S-Gamut* colourspace whitepoint name as illuminant.
S_GAMUT_ILLUMINANT : unicode
"""
S_GAMUT_WHITEPOINT = ILLUMINANTS.get(
'CIE 1931 2 Degree Standard Observer').get(S_GAMUT_ILLUMINANT)
"""
*S-Gamut* colourspace whitepoint.
S_GAMUT_WHITEPOINT : tuple
"""
S_GAMUT_TO_XYZ_MATRIX = normalised_primary_matrix(S_GAMUT_PRIMARIES,
S_GAMUT_WHITEPOINT)
"""
*S-Gamut* colourspace to *CIE XYZ* colourspace matrix.
S_GAMUT_TO_XYZ_MATRIX : array_like, (3, 3)
"""
XYZ_TO_S_GAMUT_MATRIX = np.linalg.inv(S_GAMUT_TO_XYZ_MATRIX)
"""
*CIE XYZ* colourspace to *S-Gamut* colourspace matrix.
XYZ_TO_S_GAMUT_MATRIX : array_like, (3, 3)
"""
def _s_log_transfer_function(value):
"""
Defines *S-Log* colourspace transfer function [1]_.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
return (0.432699 * np.log10(value + 0.037584) + 0.616596) + 0.03
def _s_log_inverse_transfer_function(value):
"""
Defines *S-Log* colourspace inverse transfer function [1]_.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
return 10 ** ((value - 0.616596 - 0.03) / 0.432699) - 0.037584
S_LOG_TRANSFER_FUNCTION = _s_log_transfer_function
"""
Transfer function from linear to *S-Log* colourspace.
S_LOG_TRANSFER_FUNCTION : object
"""
S_LOG_INVERSE_TRANSFER_FUNCTION = (
_s_log_inverse_transfer_function)
"""
Inverse transfer function from *S-Log* colourspace to linear.
S_LOG_INVERSE_TRANSFER_FUNCTION : object
"""
def _s_log2_transfer_function(value):
"""
Defines the *S-Log2* colourspace transfer function.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
return ((4 * (16 + 219 * (0.616596 + 0.03 + 0.432699 *
(np.log10(0.037584 + value / 0.9))))) / 1023)
def _s_log2_inverse_transfer_function(value):
"""
Defines the *S-Log2* colourspace inverse transfer function.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
return ((10 ** (((((value * 1023 / 4 - 16) / 219) - 0.616596 - 0.03)
/ 0.432699)) - 0.037584) * 0.9)
S_LOG2_TRANSFER_FUNCTION = _s_log2_transfer_function
"""
Transfer function from linear to *S-Log2* colourspace.
S_LOG2_TRANSFER_FUNCTION : object
"""
S_LOG2_INVERSE_TRANSFER_FUNCTION = _s_log2_inverse_transfer_function
"""
Inverse transfer function from *S-Log2* colourspace to linear.
S_LOG2_INVERSE_TRANSFER_FUNCTION : object
"""
S_GAMUT_COLOURSPACE = RGB_Colourspace(
'S-Gamut',
S_GAMUT_PRIMARIES,
S_GAMUT_WHITEPOINT,
S_GAMUT_ILLUMINANT,
S_GAMUT_TO_XYZ_MATRIX,
XYZ_TO_S_GAMUT_MATRIX,
S_LOG2_TRANSFER_FUNCTION,
S_LOG2_INVERSE_TRANSFER_FUNCTION)
"""
*S-Gamut* colourspace.
S_GAMUT_COLOURSPACE : RGB_Colourspace
"""
def _s_log3_transfer_function(value):
"""
Defines the *S-Log3* colourspace transfer function.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
if value >= 0.01125000:
return (420 + np.log10((value + 0.01) / (0.18 + 0.01)) * 261.5) / 1023
else:
return (value * (171.2102946929 - 95) / 0.01125000 + 95) / 1023
def _s_log3_inverse_transfer_function(value):
"""
Defines the *S-Log3* colourspace inverse transfer function.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
if value >= 171.2102946929 / 1023:
return (10 ** ((value * 1023 - 420) / 261.5)) * (0.18 + 0.01) - 0.01
else:
return (value * 1023 - 95) * 0.01125000 / (171.2102946929 - 95)
S_LOG3_TRANSFER_FUNCTION = _s_log3_transfer_function
"""
Transfer function from linear to *S-Log3* colourspace.
S_LOG3_TRANSFER_FUNCTION : object
"""
S_LOG3_INVERSE_TRANSFER_FUNCTION = _s_log3_inverse_transfer_function
"""
Inverse transfer function from *S-Log3* colourspace to linear.
S_LOG3_INVERSE_TRANSFER_FUNCTION : object
"""
S_GAMUT3_COLOURSPACE = RGB_Colourspace(
'S-Gamut3',
S_GAMUT_PRIMARIES,
S_GAMUT_WHITEPOINT,
S_GAMUT_ILLUMINANT,
S_GAMUT_TO_XYZ_MATRIX,
XYZ_TO_S_GAMUT_MATRIX,
S_LOG3_TRANSFER_FUNCTION,
S_LOG3_INVERSE_TRANSFER_FUNCTION)
"""
*S-Gamut3* colourspace.
S_GAMUT3_COLOURSPACE : RGB_Colourspace
"""
S_GAMUT3_CINE_PRIMARIES = np.array(
[[0.76600, 0.27500],
[0.22500, 0.80000],
[0.08900, -0.08700]])
"""
*S-Gamut3.Cine* colourspace primaries.
S_GAMUT_PRIMARIES : ndarray, (3, 2)
"""
S_GAMUT3_CINE_ILLUMINANT = S_GAMUT_ILLUMINANT
"""
*S-Gamut3.Cine* colourspace whitepoint name as illuminant.
S_GAMUT3_CINE_ILLUMINANT : unicode
"""
S_GAMUT3_CINE_WHITEPOINT = S_GAMUT_WHITEPOINT
"""
*S-Gamut3.Cine* colourspace whitepoint.
S_GAMUT3_CINE_WHITEPOINT : tuple
"""
S_GAMUT3_CINE_TO_XYZ_MATRIX = normalised_primary_matrix(
S_GAMUT3_CINE_PRIMARIES,
S_GAMUT3_CINE_WHITEPOINT)
"""
*S-Gamut3.Cine* colourspace to *CIE XYZ* colourspace matrix.
S_GAMUT3_CINE_TO_XYZ_MATRIX : array_like, (3, 3)
"""
XYZ_TO_S_GAMUT3_CINE_MATRIX = np.linalg.inv(S_GAMUT3_CINE_TO_XYZ_MATRIX)
"""
*CIE XYZ* colourspace to *S-Gamut3.Cine* colourspace matrix.
XYZ_TO_S_GAMUT3_CINE_MATRIX : array_like, (3, 3)
"""
S_GAMUT3_CINE_COLOURSPACE = RGB_Colourspace(
'S-Gamut3.Cine',
S_GAMUT3_CINE_PRIMARIES,
S_GAMUT3_CINE_WHITEPOINT,
S_GAMUT3_CINE_ILLUMINANT,
S_GAMUT3_CINE_TO_XYZ_MATRIX,
XYZ_TO_S_GAMUT3_CINE_MATRIX,
S_LOG3_TRANSFER_FUNCTION,
S_LOG3_INVERSE_TRANSFER_FUNCTION)
"""
*S-Gamut3.Cine* colourspace.
S_GAMUT3_CINE_COLOURSPACE : RGB_Colourspace
"""
Colour 0.3