#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
CIE RGB Colourspace
===================
Defines the *CIE RGB* colourspace:
- :attr:`CIE_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] Wikipedia. (n.d.). Construction of the CIE XYZ color space from the
Wright–Guild data. Retrieved February 24, 2014, from
http://en.wikipedia.org/wiki/CIE_1931_color_space#Construction_of_the_CIE_XYZ_color_space_from_the_Wright.E2.80.93Guild_data # noqa
"""
from __future__ import division, unicode_literals
import numpy as np
from colour.colorimetry import ILLUMINANTS
from colour.models import RGB_Colourspace
__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__ = ['CIE_RGB_PRIMARIES',
'CIE_RGB_ILLUMINANT',
'CIE_RGB_WHITEPOINT',
'CIE_RGB_TO_XYZ_MATRIX',
'XYZ_TO_CIE_RGB_MATRIX',
'CIE_RGB_TRANSFER_FUNCTION',
'CIE_RGB_INVERSE_TRANSFER_FUNCTION',
'CIE_RGB_COLOURSPACE']
CIE_RGB_PRIMARIES = np.array(
[[0.7350, 0.2650],
[0.2740, 0.7170],
[0.1670, 0.0090]])
"""
*CIE RGB* colourspace primaries.
CIE_RGB_PRIMARIES : ndarray, (3, 2)
"""
CIE_RGB_ILLUMINANT = 'E'
"""
*CIE RGB* colourspace whitepoint name as illuminant.
CIE_RGB_ILLUMINANT : unicode
"""
CIE_RGB_WHITEPOINT = ILLUMINANTS.get(
'CIE 1931 2 Degree Standard Observer').get(CIE_RGB_ILLUMINANT)
"""
*CIE RGB* colourspace whitepoint.
CIE_RGB_WHITEPOINT : tuple
"""
CIE_RGB_TO_XYZ_MATRIX = np.array([[0.4887180, 0.3106803, 0.2006017],
[0.1762044, 0.8129847, 0.0108109],
[0.0000000, 0.0102048, 0.9897952]])
"""
*CIE RGB* colourspace to *CIE XYZ* tristimulus values matrix.
CIE_RGB_TO_XYZ_MATRIX : array_like, (3, 3)
"""
XYZ_TO_CIE_RGB_MATRIX = np.linalg.inv(CIE_RGB_TO_XYZ_MATRIX)
"""
*CIE XYZ* tristimulus values to *CIE RGB* colourspace matrix.
XYZ_TO_CIE_RGB_MATRIX : array_like, (3, 3)
"""
def _cie_rgb_transfer_function(value):
"""
Defines the *CIE RGB* colourspace transfer function.
Parameters
----------
value : numeric or array_like
Value.
Returns
-------
numeric or ndarray
Companded value.
"""
value = np.asarray(value)
return value ** (1 / 2.2)
def _cie_rgb_inverse_transfer_function(value):
"""
Defines the *CIE RGB* colourspace inverse transfer function.
Parameters
----------
value : numeric or array_like
Value.
Returns
-------
numeric or ndarray
Companded value.
"""
value = np.asarray(value)
return value ** 2.2
CIE_RGB_TRANSFER_FUNCTION = _cie_rgb_transfer_function
"""
Transfer function from linear to *CIE RGB* colourspace.
CIE_RGB_TRANSFER_FUNCTION : object
"""
CIE_RGB_INVERSE_TRANSFER_FUNCTION = _cie_rgb_inverse_transfer_function
"""
Inverse transfer function from *CIE RGB* colourspace to linear.
CIE_RGB_INVERSE_TRANSFER_FUNCTION : object
"""
CIE_RGB_COLOURSPACE = RGB_Colourspace(
'CIE RGB',
CIE_RGB_PRIMARIES,
CIE_RGB_WHITEPOINT,
CIE_RGB_ILLUMINANT,
CIE_RGB_TO_XYZ_MATRIX,
XYZ_TO_CIE_RGB_MATRIX,
CIE_RGB_TRANSFER_FUNCTION,
CIE_RGB_INVERSE_TRANSFER_FUNCTION)
"""
*CIE RGB* colourspace.
CIE_RGB_COLOURSPACE : RGB_Colourspace
"""
Colour 0.3