"""
RGB Colourspace & Transformations
=================================
Defines the following *RGB* colourspace transformations:
- :func:`colour_hdri.camera_space_to_RGB`
- :func:`colour_hdri.camera_space_to_sRGB`
"""
from __future__ import annotations
import numpy as np
from colour.algebra import matrix_dot, vector_dot
from colour.hints import ArrayLike, NDArrayFloat
from colour.models import RGB_COLOURSPACES
__author__ = "Colour Developers"
__copyright__ = "Copyright 2015 Colour Developers"
__license__ = "BSD-3-Clause - https://opensource.org/licenses/BSD-3-Clause"
__maintainer__ = "Colour Developers"
__email__ = "colour-developers@colour-science.org"
__status__ = "Production"
__all__ = [
"camera_space_to_RGB",
"camera_space_to_sRGB",
]
[docs]
def camera_space_to_RGB(
RGB: ArrayLike,
M_XYZ_to_camera_space: ArrayLike,
matrix_RGB_to_XYZ: ArrayLike,
) -> NDArrayFloat:
"""
Convert given *RGB* array from *camera space* to given *RGB* colourspace.
Parameters
----------
RGB
Camera space *RGB* colourspace array.
M_XYZ_to_camera_space
Matrix converting from *CIE XYZ* tristimulus values to *camera space*.
matrix_RGB_to_XYZ
Matrix converting from *RGB* colourspace to *CIE XYZ* tristimulus
values.
Returns
-------
:class:`numpy.ndarray`
*RGB* colourspace array.
Examples
--------
>>> RGB = np.array([0.80660, 0.81638, 0.65885])
>>> M_XYZ_to_camera_space = np.array(
... [
... [0.47160000, 0.06030000, -0.08300000],
... [-0.77980000, 1.54740000, 0.24800000],
... [-0.14960000, 0.19370000, 0.66510000],
... ]
... )
>>> matrix_RGB_to_XYZ = np.array(
... [
... [0.41238656, 0.35759149, 0.18045049],
... [0.21263682, 0.71518298, 0.07218020],
... [0.01933062, 0.11919716, 0.95037259],
... ]
... )
>>> camera_space_to_RGB(
... RGB, M_XYZ_to_camera_space, matrix_RGB_to_XYZ
... ) # doctest: +ELLIPSIS
array([ 0.7564180..., 0.8683192..., 0.6044589...])
"""
M_RGB_camera = matrix_dot(M_XYZ_to_camera_space, matrix_RGB_to_XYZ)
M_RGB_camera /= np.transpose(np.sum(M_RGB_camera, axis=1)[None])
RGB_f = vector_dot(np.linalg.inv(M_RGB_camera), RGB)
return RGB_f
[docs]
def camera_space_to_sRGB(
RGB: ArrayLike, M_XYZ_to_camera_space: ArrayLike
) -> NDArrayFloat:
"""
Convert given *RGB* array from *camera space* to *sRGB* colourspace.
Parameters
----------
RGB
Camera space *RGB* colourspace array.
M_XYZ_to_camera_space
Matrix converting from *CIE XYZ* tristimulus values to *camera space*.
Returns
-------
:class:`numpy.ndarray`
*sRGB* colourspace array.
Examples
--------
>>> RGB = np.array([0.80660, 0.81638, 0.65885])
>>> M_XYZ_to_camera_space = np.array(
... [
... [0.47160000, 0.06030000, -0.08300000],
... [-0.77980000, 1.54740000, 0.24800000],
... [-0.14960000, 0.19370000, 0.66510000],
... ]
... )
>>> camera_space_to_sRGB(RGB, M_XYZ_to_camera_space) # doctest: +ELLIPSIS
array([ 0.7564350..., 0.8683155..., 0.6044706...])
"""
return camera_space_to_RGB(
RGB, M_XYZ_to_camera_space, RGB_COLOURSPACES["sRGB"].matrix_RGB_to_XYZ
)