aces_1.0.0/python/aces_ocio/create_panasonic_colorspaces.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 Implements support for *Panasonic* colorspaces conversions and transfer functions.
   6 """
   7
   8 import array
   9 import os
  10
  11 import PyOpenColorIO as ocio
  12
  13 import aces_ocio.generate_lut as genlut
  14 from aces_ocio.utilities import ColorSpace
  15
  16 __author__ = 'ACES Developers'
  17 __copyright__ = 'Copyright (C) 2014 - 2015 - ACES Developers'
  18 __license__ = ''
  19 __maintainer__ = 'ACES Developers'
  20 __email__ = 'aces@oscars.org'
  21 __status__ = 'Production'
  22
  23 __all__ = ['create_v_log',
  24            'create_colorspaces']
  25
  26
  27 def create_v_log(gamut,
  28                  transfer_function,
  29                  name,
  30                  lut_directory,
  31                  lut_resolution_1d,
  32                  aliases):
  33     """
  34     Object description.
  35
  36     Panasonic V-Log to ACES.
  37
  38     Parameters
  39     ----------
  40     parameter : type
  41         Parameter description.
  42
  43     Returns
  44     -------
  45     type
  46          Return value description.
  47     """
  48
  49     name = '%s - %s' % (transfer_function, gamut)
  50     if transfer_function == '':
  51         name = 'Linear - %s' % gamut
  52     if gamut == '':
  53         name = '%s' % transfer_function
  54
  55     cs = ColorSpace(name)
  56     cs.description = name
  57     cs.aliases = aliases
  58     cs.equality_group = ''
  59     cs.family = 'Panasonic'
  60     cs.is_data = False
  61
  62     # A linear space needs allocation variables
  63     if transfer_function == '':
  64         cs.allocation_type = ocio.Constants.ALLOCATION_LG2
  65         cs.allocation_vars = [-8, 5, 0.00390625]
  66
  67     def v_log_to_linear(x):
  68         cutInv = 0.181
  69         b = 0.00873
  70         c = 0.241514
  71         d = 0.598206
  72
  73         if (x <= cutInv):
  74             return (x - 0.125) / 5.6
  75         else:
  76             return pow(10, (x-d)/c) - b
  77
  78     cs.to_reference_transforms = []
  79
  80     if transfer_function == 'V-Log':
  81         data = array.array('f', '\0' * lut_resolution_1d * 4)
  82         for c in range(lut_resolution_1d):
  83             data[c] = v_log_to_linear(float(c) / (lut_resolution_1d - 1))
  84
  85         lut = '%s_to_linear.spi1d' % transfer_function
  86         genlut.write_SPI_1d(
  87             os.path.join(lut_directory, lut),
  88             0.0,
  89             1.0,
  90             data,
  91             lut_resolution_1d,
  92             1)
  93
  94         cs.to_reference_transforms.append({
  95             'type': 'lutFile',
  96             'path': lut,
  97             'interpolation': 'linear',
  98             'direction': 'forward'})
  99
 100     if gamut == 'V-Gamut':
 101         cs.to_reference_transforms.append({
 102             'type': 'matrix',
 103             'matrix': [ 0.724382758,  0.166748484,  0.108497411, 0.0,
 104                         0.021354009,  0.985138372, -0.006319092, 0.0,
 105                        -0.009234278, -0.00104295,   1.010272625, 0.0,
 106                         0, 0, 0, 1.0],
 107             'direction': 'forward'})
 108
 109     cs.from_reference_transforms = []
 110     return cs
 111
 112
 113 def create_colorspaces(lut_directory, lut_resolution_1d):
 114     """
 115     Generates the colorspace conversions.
 116
 117     Parameters
 118     ----------
 119     parameter : type
 120         Parameter description.
 121
 122     Returns
 123     -------
 124     type
 125          Return value description.
 126     """
 127
 128     colorspaces = []
 129
 130     # Full conversion
 131     v_log_1 = create_v_log(
 132         'V-Gamut',
 133         'V-Log',
 134         'V-Log',
 135         lut_directory,
 136         lut_resolution_1d,
 137         ["vlog_vgamut"])
 138     colorspaces.append(v_log_1)
 139
 140     # Linearization Only
 141     v_log_2 = create_v_log(
 142         '',
 143         'V-Log',
 144         'V-Log',
 145         lut_directory,
 146         lut_resolution_1d,
 147         ["crv_vlog"])
 148     colorspaces.append(v_log_2)
 149
 150     # Primaries Only
 151     v_log_3 = create_v_log(
 152         'V-Gamut',
 153         '',
 154         'V-Log',
 155         lut_directory,
 156         lut_resolution_1d,
 157         ["lin_vgamut"])
 158     colorspaces.append(v_log_3)
 159
 160     return colorspaces