#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
ALEXA Wide Gamut RGB Colourspace
================================
Defines the *ALEXA Wide Gamut RGB* colourspace:
- :attr:`ALEXA_WIDE_GAMUT_RGB_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] ARRI. (2012). ALEXA - Log C Curve - Usage in VFX. Retrieved from
http://www.arri.com/?eID=registration&file_uid=8026
"""
from __future__ import division, unicode_literals
import numpy as np
from colour.colorimetry import ILLUMINANTS
from colour.models import RGB_Colourspace
from colour.utilities import CaseInsensitiveMapping
__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__ = ['ALEXA_LOG_C_CURVE_BCL_DATA',
'ALEXA_LOG_C_CURVE_CONVERSION_DATA',
'ALEXA_WIDE_GAMUT_RGB_PRIMARIES',
'ALEXA_WIDE_GAMUT_RGB_ILLUMINANT',
'ALEXA_WIDE_GAMUT_RGB_WHITEPOINT',
'ALEXA_WIDE_GAMUT_RGB_TO_XYZ_MATRIX',
'XYZ_TO_ALEXA_WIDE_GAMUT_RGB_MATRIX',
'ALEXA_LOG_C_TRANSFER_FUNCTION',
'ALEXA_LOG_C_INVERSE_TRANSFER_FUNCTION',
'ALEXA_WIDE_GAMUT_RGB_COLOURSPACE']
ALEXA_LOG_C_CURVE_BCL_DATA = CaseInsensitiveMapping(
{'SUP 3.x': {
160: (0.0928, 0.8128),
200: (0.0928, 0.8341),
250: (0.0928, 0.8549),
320: (0.0928, 0.8773),
400: (0.0928, 0.8968),
500: (0.0928, 0.9158),
640: (0.0928, 0.9362),
800: (0.0928, 0.9539),
1000: (0.0928, 0.9711),
1280: (0.0928, 0.9895),
1600: (0.0928, 1.0000),
2000: (0.0928, 1.0000),
2560: (0.0928, 1.0000),
3200: (0.0928, 1.0000)},
'SUP 2.x': {
160: (0.1083, 0.8110),
200: (0.1115, 0.8320),
250: (0.1146, 0.8524),
320: (0.1181, 0.8743),
400: (0.1213, 0.8935),
500: (0.1245, 0.9121),
640: (0.1280, 0.9320),
800: (0.1311, 0.9494),
1000: (0.1343, 0.9662),
1280: (0.1378, 0.9841),
1600: (0.1409, 0.9997)}})
"""
*ALEXA Log C* curve *Ei, Black, Clipping Level* data.
ALEXA_LOG_C_CURVE_BCL_DATA : CaseInsensitiveMapping
{'SUP 3.x', 'SUP 2.x'}
"""
# @formatter:off
ALEXA_LOG_C_CURVE_CONVERSION_DATA = CaseInsensitiveMapping(
{'SUP 3.x': CaseInsensitiveMapping(
{'Normalised Sensor Signal': {
160: (0.004680, 40.0, -0.076072, 0.269036, 0.381991, 42.062665, -0.071569, 0.125266), # noqa
200: (0.004597, 50.0, -0.118740, 0.266007, 0.382478, 51.986387, -0.110339, 0.128643), # noqa
250: (0.004518, 62.5, -0.171260, 0.262978, 0.382966, 64.243053, -0.158224, 0.132021), # noqa
320: (0.004436, 80.0, -0.243808, 0.259627, 0.383508, 81.183335, -0.224409, 0.135761), # noqa
400: (0.004369, 100.0, -0.325820, 0.256598, 0.383999, 100.295280, -0.299079, 0.139142), # noqa
500: (0.004309, 125.0, -0.427461, 0.253569, 0.384493, 123.889239, -0.391261, 0.142526), # noqa
640: (0.004249, 160.0, -0.568709, 0.250219, 0.385040, 156.482680, -0.518605, 0.146271), # noqa
800: (0.004201, 200.0, -0.729169, 0.247190, 0.385537, 193.235573, -0.662201, 0.149658), # noqa
1000: (0.004160, 250.0, -0.928805, 0.244161, 0.386036, 238.584745, -0.839385, 0.153047), # noqa
1280: (0.004120, 320.0, -1.207168, 0.240810, 0.386590, 301.197380, -1.084020, 0.156799), # noqa
1600: (0.004088, 400.0, -1.524256, 0.237781, 0.387093, 371.761171, -1.359723, 0.160192)}, # noqa
'Linear Scene Exposure Factor': {
160: (0.005561, 5.555556, 0.080216, 0.269036, 0.381991, 5.842037, 0.092778, 0.125266), # noqa
200: (0.006208, 5.555556, 0.076621, 0.266007, 0.382478, 5.776265, 0.092782, 0.128643), # noqa
250: (0.006871, 5.555556, 0.072941, 0.262978, 0.382966, 5.710494, 0.092786, 0.132021), # noqa
320: (0.007622, 5.555556, 0.068768, 0.259627, 0.383508, 5.637732, 0.092791, 0.135761), # noqa
400: (0.008318, 5.555556, 0.064901, 0.256598, 0.383999, 5.571960, 0.092795, 0.139142), # noqa
500: (0.009031, 5.555556, 0.060939, 0.253569, 0.384493, 5.506188, 0.092800, 0.142526), # noqa
640: (0.009840, 5.555556, 0.056443, 0.250219, 0.385040, 5.433426, 0.092805, 0.146271), # noqa
800: (0.010591, 5.555556, 0.052272, 0.247190, 0.385537, 5.367655, 0.092809, 0.149658), # noqa
1000: (0.011361, 5.555556, 0.047996, 0.244161, 0.386036, 5.301883, 0.092814, 0.153047), # noqa
1280: (0.012235, 5.555556, 0.043137, 0.240810, 0.386590, 5.229121, 0.092819, 0.156799), # noqa
1600: (0.013047, 5.555556, 0.038625, 0.237781, 0.387093, 5.163350, 0.092824, 0.16019)}}), # noqa
'SUP 2.x': CaseInsensitiveMapping(
{'Normalised Sensor Signal': {
160: (0.003907, 36.439829, -0.053366, 0.269035, 0.391007, 45.593473, -0.069772, 0.10836), # noqa
200: (0.003907, 45.549786, -0.088959, 0.266007, 0.391007, 55.709581, -0.106114, 0.11154), # noqa
250: (0.003907, 56.937232, -0.133449, 0.262978, 0.391007, 67.887153, -0.150510, 0.11472), # noqa
320: (0.003907, 72.879657, -0.195737, 0.259627, 0.391007, 84.167616, -0.210597, 0.11824), # noqa
400: (0.003907, 91.099572, -0.266922, 0.256598, 0.391007, 101.811426, -0.276349, 0.12142), # noqa
500: (0.003907, 113.874465, -0.355903, 0.253569, 0.391007, 122.608379, -0.354421, 0.12461), # noqa
640: (0.003907, 145.759315, -0.480477, 0.250218, 0.391007, 149.703304, -0.456760, 0.12813), # noqa
800: (0.003907, 182.199144, -0.622848, 0.247189, 0.391007, 178.216873, -0.564981, 0.13131), # noqa
1000: (0.003907, 227.748930, -0.800811, 0.244161, 0.391007, 210.785040, -0.689043, 0.13449), # noqa
1280: (0.003907, 291.518630, -1.049959, 0.240810, 0.391007, 251.689459, -0.845336, 0.13801), # noqa
1600: (0.003907, 364.398287, -1.334700, 0.237781, 0.391007, 293.073575, -1.003841, 0.14119)}, # noqa
'Linear Scene Exposure Factor': {
160: (0.000000, 5.061087, 0.089004, 0.269035, 0.391007, 6.332427, 0.108361, 0.108361), # noqa
200: (0.000000, 5.061087, 0.089004, 0.266007, 0.391007, 6.189953, 0.111543, 0.111543), # noqa
250: (0.000000, 5.061087, 0.089004, 0.262978, 0.391007, 6.034414, 0.114725, 0.114725), # noqa
320: (0.000000, 5.061087, 0.089004, 0.259627, 0.391007, 5.844973, 0.118246, 0.118246), # noqa
400: (0.000000, 5.061087, 0.089004, 0.256598, 0.391007, 5.656190, 0.121428, 0.121428), # noqa
500: (0.000000, 5.061087, 0.089004, 0.253569, 0.391007, 5.449261, 0.124610, 0.124610), # noqa
640: (0.000000, 5.061087, 0.089004, 0.250218, 0.391007, 5.198031, 0.128130, 0.128130), # noqa
800: (0.000000, 5.061087, 0.089004, 0.247189, 0.391007, 4.950469, 0.131313, 0.131313), # noqa
1000: (0.000000, 5.061087, 0.089004, 0.244161, 0.391007, 4.684112, 0.134495, 0.134495), # noqa
1280: (0.000000, 5.061087, 0.089004, 0.240810, 0.391007, 4.369609, 0.138015, 0.138015), # noqa
1600: (0.000000, 5.061087, 0.089004, 0.237781, 0.391007, 4.070466, 0.141197, 0.14119)}})}) # noqa
"""
*ALEXA Log C* curve conversion data between signal and linear scene exposure
factor for *SUP 3.x* and signal and normalized sensor signal for *SUP 2.x*.
ALEXA_LOG_C_CURVE_CONVERSION_DATA : CaseInsensitiveMapping
{'SUP 3.x', 'SUP 2.x'}
"""
# @formatter:on
ALEXA_WIDE_GAMUT_RGB_PRIMARIES = np.array(
[[0.6840, 0.3130],
[0.2210, 0.8480],
[0.0861, -0.1020]])
"""
*ALEXA Wide Gamut RGB* colourspace primaries.
ALEXA_WIDE_GAMUT_RGB_PRIMARIES : ndarray, (3, 2)
"""
ALEXA_WIDE_GAMUT_RGB_ILLUMINANT = 'D65'
"""
*ALEXA Wide Gamut RGB* colourspace whitepoint name as illuminant.
ALEXA_WIDE_GAMUT_RGB_WHITEPOINT : unicode
"""
ALEXA_WIDE_GAMUT_RGB_WHITEPOINT = ILLUMINANTS.get(
'CIE 1931 2 Degree Standard Observer').get(ALEXA_WIDE_GAMUT_RGB_ILLUMINANT)
"""
*ALEXA Wide Gamut RGB* colourspace whitepoint.
ALEXA_WIDE_GAMUT_RGB_WHITEPOINT : tuple
"""
ALEXA_WIDE_GAMUT_RGB_TO_XYZ_MATRIX = np.array(
[[0.638008, 0.214704, 0.097744],
[0.291954, 0.823841, -0.115795],
[0.002798, -0.067034, 1.153294]])
"""
*ALEXA Wide Gamut RGB* colourspace to *CIE XYZ* tristimulus values matrix.
ALEXA_WIDE_GAMUT_RGB_TO_XYZ_MATRIX : array_like, (3, 3)
"""
XYZ_TO_ALEXA_WIDE_GAMUT_RGB_MATRIX = np.linalg.inv(
ALEXA_WIDE_GAMUT_RGB_TO_XYZ_MATRIX)
"""
*CIE XYZ* tristimulus values to *ALEXA Wide Gamut RGB* colourspace matrix.
XYZ_TO_ALEXA_WIDE_GAMUT_RGB_MATRIX : array_like, (3, 3)
"""
def _linear_to_alexa_log_c(
value,
firmware='SUP 3.x',
method='Linear Scene Exposure Factor',
EI=800):
"""
Defines the *linear* to *ALEXA Log C* conversion function.
Parameters
----------
value : numeric or array_like
Value.
firmware : unicode, optional
{'SUP 3.x', 'SUP 2.x'}
Alexa firmware version.
method : unicode, optional
{'Linear Scene Exposure Factor', 'Normalised Sensor Signal'}
Conversion method.
EI : int, optional
Ei.
Returns
-------
numeric or ndarray
Companded value.
"""
value = np.asarray(value)
cut, a, b, c, d, e, f, _ = ALEXA_LOG_C_CURVE_CONVERSION_DATA.get(
firmware).get(method).get(EI)
return np.where(value > cut,
c * np.log10(a * value + b) + d,
e * value + f)
def _alexa_log_c_to_linear(
value,
firmware='SUP 3.x',
method='Linear Scene Exposure Factor',
EI=800):
"""
Defines the *ALEXA Log C* to *linear* conversion function.
Parameters
----------
value : numeric or array_like
Value.
firmware : unicode, optional
{'SUP 3.x', 'SUP 2.x'}
Alexa firmware version.
method : unicode, optional
{'Linear Scene Exposure Factor', 'Normalised Sensor Signal'}
Conversion method.
EI : int, optional
Ei.
Returns
-------
numeric or ndarray
Companded value.
"""
value = np.asarray(value)
cut, a, b, c, d, e, f, _ = (
ALEXA_LOG_C_CURVE_CONVERSION_DATA.get(firmware).get(method).get(EI))
return np.where(value > e * cut + f,
(np.power(10, (value - d) / c) - b) / a,
(value - f) / e)
ALEXA_LOG_C_TRANSFER_FUNCTION = _linear_to_alexa_log_c
"""
Transfer function from linear to *ALEXA Log C*.
ALEXA_LOG_C_TRANSFER_FUNCTION : object
"""
ALEXA_LOG_C_INVERSE_TRANSFER_FUNCTION = _alexa_log_c_to_linear
"""
Inverse transfer function from *ALEXA Log C* to linear.
ALEXA_LOG_C_INVERSE_TRANSFER_FUNCTION : object
"""
ALEXA_WIDE_GAMUT_RGB_COLOURSPACE = RGB_Colourspace(
'ALEXA Wide Gamut RGB',
ALEXA_WIDE_GAMUT_RGB_PRIMARIES,
ALEXA_WIDE_GAMUT_RGB_WHITEPOINT,
ALEXA_WIDE_GAMUT_RGB_ILLUMINANT,
ALEXA_WIDE_GAMUT_RGB_TO_XYZ_MATRIX,
XYZ_TO_ALEXA_WIDE_GAMUT_RGB_MATRIX,
ALEXA_LOG_C_TRANSFER_FUNCTION,
ALEXA_LOG_C_INVERSE_TRANSFER_FUNCTION)
"""
*ALEXA Wide Gamut RGB* colourspace.
ALEXA_WIDE_GAMUT_RGB_COLOURSPACE : RGB_Colourspace
"""
Colour 0.3