#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Don RGB 4 Colourspace
=====================
Defines the *Don RGB 4* colourspace:
- :attr:`DON_RGB_4_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] HutchColor. (n.d.). DonRGB4 (4 K). Retrieved from
http://www.hutchcolor.com/profiles/DonRGB4.zip
"""
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__ = ['DON_RGB_4_PRIMARIES',
'DON_RGB_4_ILLUMINANT',
'DON_RGB_4_WHITEPOINT',
'DON_RGB_4_TO_XYZ_MATRIX',
'XYZ_TO_DON_RGB_4_MATRIX',
'DON_RGB_4_TRANSFER_FUNCTION',
'DON_RGB_4_INVERSE_TRANSFER_FUNCTION',
'DON_RGB_4_COLOURSPACE']
DON_RGB_4_PRIMARIES = np.array(
[[0.69612068965517238, 0.29956896551724138],
[0.21468298109010012, 0.7652947719688542],
[0.12993762993762992, 0.035343035343035345]])
"""
*Don RGB 4* colourspace primaries.
DON_RGB_4_PRIMARIES : ndarray, (3, 2)
"""
DON_RGB_4_ILLUMINANT = 'D50'
"""
*Don RGB 4* colourspace whitepoint name as illuminant.
DON_RGB_4_ILLUMINANT : unicode
"""
DON_RGB_4_WHITEPOINT = ILLUMINANTS.get(
'CIE 1931 2 Degree Standard Observer').get(DON_RGB_4_ILLUMINANT)
"""
*Don RGB 4* colourspace whitepoint.
DON_RGB_4_WHITEPOINT : tuple
"""
DON_RGB_4_TO_XYZ_MATRIX = normalised_primary_matrix(DON_RGB_4_PRIMARIES,
DON_RGB_4_WHITEPOINT)
"""
*Don RGB 4* colourspace to *CIE XYZ* colourspace matrix.
DON_RGB_4_TO_XYZ_MATRIX : array_like, (3, 3)
"""
XYZ_TO_DON_RGB_4_MATRIX = np.linalg.inv(DON_RGB_4_TO_XYZ_MATRIX)
"""
*CIE XYZ* colourspace to *Don RGB 4* colourspace matrix.
XYZ_TO_DON_RGB_4_MATRIX : array_like, (3, 3)
"""
def _don_rgb_4_transfer_function(value):
"""
Defines the *Don RGB 4* colourspace transfer function.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
return value ** (1 / 2.2)
def _don_rgb_4_inverse_transfer_function(value):
"""
Defines the *Don RGB 4* colourspace inverse transfer
function.
Parameters
----------
value : numeric
Value.
Returns
-------
numeric
Companded value.
"""
return value ** 2.2
DON_RGB_4_TRANSFER_FUNCTION = _don_rgb_4_transfer_function
"""
Transfer function from linear to *Don RGB 4* colourspace.
DON_RGB_4_TRANSFER_FUNCTION : object
"""
DON_RGB_4_INVERSE_TRANSFER_FUNCTION = _don_rgb_4_inverse_transfer_function
"""
Inverse transfer function from *Don RGB 4* colourspace to linear.
DON_RGB_4_INVERSE_TRANSFER_FUNCTION : object
"""
DON_RGB_4_COLOURSPACE = RGB_Colourspace(
'Don RGB 4',
DON_RGB_4_PRIMARIES,
DON_RGB_4_WHITEPOINT,
DON_RGB_4_ILLUMINANT,
DON_RGB_4_TO_XYZ_MATRIX,
XYZ_TO_DON_RGB_4_MATRIX,
DON_RGB_4_TRANSFER_FUNCTION,
DON_RGB_4_INVERSE_TRANSFER_FUNCTION)
"""
*Don RGB 4* colourspace.
DON_RGB_4_COLOURSPACE : RGB_Colourspace
"""
Colour 0.3