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#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Implements support for *GoPro* colorspaces conversions and transfer functions.
"""
from __future__ import division
import array
import os
import PyOpenColorIO as ocio
import aces_ocio.generate_lut as genlut
from aces_ocio.utilities import (ColorSpace, sanitize)
__author__ = 'ACES Developers'
__copyright__ = 'Copyright (C) 2014 - 2016 - ACES Developers'
__license__ = ''
__maintainer__ = 'ACES Developers'
__email__ = 'aces@oscars.org'
__status__ = 'Production'
__all__ = ['create_protune',
'create_colorspaces']
def create_protune(gamut,
transfer_function,
lut_directory,
lut_resolution_1d,
aliases):
"""
Creates colorspace covering the conversion from ProTune to ACES, with
various transfer functions and encoding gamuts covered.
Parameters
----------
gamut : str
The name of the encoding gamut to use.
transfer_function : str
The name of the transfer function to use.
lut_directory : str or unicode
The directory to use when generating LUTs.
lut_resolution_1d : int
The resolution of generated 1D LUTs.
aliases : list of str
Aliases for this colorspace.
Returns
-------
ColorSpace
A ColorSpace container class referencing the LUTs, matrices and
identifying information for the requested colorspace.
"""
# The gamut should be marked as experimental until matrices are fully
# verified.
name = '%s - %s - Experimental' % (transfer_function, gamut)
if transfer_function == '':
name = 'Linear - %s - Experimental' % gamut
if gamut == '':
name = 'Curve - %s' % transfer_function
cs = ColorSpace(name)
cs.description = name
cs.aliases = aliases
cs.equality_group = ''
cs.family = 'Input/GoPro'
cs.is_data = False
# A linear space needs allocation variables.
if transfer_function == '':
cs.allocation_type = ocio.Constants.ALLOCATION_LG2
cs.allocation_vars = [-8, 5, 0.00390625]
def protune_to_linear(normalized_code_value):
c1 = 113.0
c2 = 1.0
c3 = 112.0
linear = ((pow(c1, normalized_code_value) - c2) / c3)
return linear
cs.to_reference_transforms = []
if transfer_function == 'Protune Flat':
data = array.array('f', '\0' * lut_resolution_1d * 4)
for c in range(lut_resolution_1d):
data[c] = protune_to_linear(float(c) / (lut_resolution_1d - 1))
lut = '%s_to_linear.spi1d' % transfer_function
lut = sanitize(lut)
genlut.write_SPI_1d(
os.path.join(lut_directory, lut),
0,
1,
data,
lut_resolution_1d,
1)
cs.to_reference_transforms.append({
'type': 'lutFile',
'path': lut,
'interpolation': 'linear',
'direction': 'forward'})
if gamut == 'Protune Native':
cs.to_reference_transforms.append({
'type': 'matrix',
'matrix': [0.533448429, 0.32413911, 0.142412421, 0,
-0.050729924, 1.07572006, -0.024990416, 0,
0.071419661, -0.290521962, 1.219102381, 0,
0, 0, 0, 1],
'direction': 'forward'})
cs.from_reference_transforms = []
return cs
def create_colorspaces(lut_directory, lut_resolution_1d):
"""
Generates the colorspace conversions.
Parameters
----------
lut_directory : str or unicode
The directory to use when generating LUTs.
lut_resolution_1d : int
The resolution of generated 1D LUTs.
Returns
-------
list
A list of colorspaces for GoPro cameras and encodings.
"""
colorspaces = []
# Full conversion
protune_1 = create_protune(
'Protune Native',
'Protune Flat',
lut_directory,
lut_resolution_1d,
['protuneflat_protunegamutexp'])
colorspaces.append(protune_1)
# Linearization Only
protune_2 = create_protune(
'',
'Protune Flat',
lut_directory,
lut_resolution_1d,
['crv_protuneflat'])
colorspaces.append(protune_2)
# Primaries Only
protune_3 = create_protune(
'Protune Native',
'',
lut_directory,
lut_resolution_1d,
['lin_protunegamutexp'])
colorspaces.append(protune_3)
return colorspaces