# -*- coding: utf-8 -*-
"""
Hexadecimal Notation
====================
Defines objects for hexadecimal notation:
- :func:`colour.notation.RGB_to_HEX`
- :func:`colour.notation.HEX_to_RGB`
"""
from __future__ import division, unicode_literals
import numpy as np
from colour.models import eotf_inverse_sRGB, eotf_sRGB
from colour.utilities import (as_float_array, from_range_1, normalise_maximum,
to_domain_1, usage_warning)
__author__ = 'Colour Developers'
__copyright__ = 'Copyright (C) 2013-2020 - Colour Developers'
__license__ = 'New BSD License - https://opensource.org/licenses/BSD-3-Clause'
__maintainer__ = 'Colour Developers'
__email__ = 'colour-developers@colour-science.org'
__status__ = 'Production'
__all__ = ['RGB_to_HEX', 'HEX_to_RGB']
[docs]def RGB_to_HEX(RGB):
"""
Converts from *RGB* colourspace to hexadecimal representation.
Parameters
----------
RGB : array_like
*RGB* colourspace array.
Returns
-------
unicode
Hexadecimal representation.
Notes
-----
+------------+-----------------------+---------------+
| **Domain** | **Scale - Reference** | **Scale - 1** |
+============+=======================+===============+
| ``RGB`` | [0, 1] | [0, 1] |
+------------+-----------------------+---------------+
Examples
--------
>>> RGB = np.array([0.66666667, 0.86666667, 1.00000000])
>>> # Doctests skip for Python 2.x compatibility.
>>> RGB_to_HEX(RGB) # doctest: +SKIP
'#aaddff'
"""
RGB = to_domain_1(RGB)
if np.any(RGB < 0):
usage_warning(
'"RGB" array contains negative values, those will be clipped, '
'unpredictable results may occur!')
RGB = np.clip(RGB, 0, np.inf)
if np.any(RGB > 1):
usage_warning(
'"RGB" array contains values over 1 and will be normalised, '
'unpredictable results may occur!')
RGB = eotf_inverse_sRGB(normalise_maximum(eotf_sRGB(RGB)))
to_HEX = np.vectorize('{0:02x}'.format)
HEX = to_HEX((RGB * 255).astype(np.uint8)).astype(object)
HEX = np.asarray('#') + HEX[..., 0] + HEX[..., 1] + HEX[..., 2]
return HEX
[docs]def HEX_to_RGB(HEX):
"""
Converts from hexadecimal representation to *RGB* colourspace.
Parameters
----------
HEX : unicode or array_like
Hexadecimal representation.
Returns
-------
ndarray
*RGB* colourspace array.
Notes
-----
+-----------+-----------------------+---------------+
| **Range** | **Scale - Reference** | **Scale - 1** |
+===========+=======================+===============+
| ``RGB`` | [0, 1] | [0, 1] |
+-----------+-----------------------+---------------+
Examples
--------
>>> HEX = '#aaddff'
>>> HEX_to_RGB(HEX) # doctest: +ELLIPSIS
array([ 0.6666666..., 0.8666666..., 1. ])
"""
HEX = np.core.defchararray.lstrip(HEX, '#')
def to_RGB(x):
"""
Converts given hexadecimal representation to *RGB*.
"""
l_x = len(x)
return [int(x[i:i + l_x // 3], 16) for i in range(0, l_x, l_x // 3)]
to_RGB_v = np.vectorize(to_RGB, otypes=[np.ndarray])
RGB = as_float_array(to_RGB_v(HEX).tolist()) / 255
return from_range_1(RGB)