RGB Colourspace Whitepoint Change

rgb_colourspace_whitepoint_change.ipynb

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  "signature": "sha256:98b4f38bd43ca2878bb71f905d912912007797b6023387b28ad4667390771111"
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 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "RGB Colourspace Whitepoint Change"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import numpy as np\n",
      "import colour\n",
      "\n",
      "NUKE_TEMPLATE = \"\"\"\n",
      "    ColorMatrix {{\n",
      "     inputs 0\n",
      "     matrix {{\n",
      "         {0}\n",
      "       }}\n",
      "     name {1}\n",
      "     selected true\n",
      "    }}\n",
      "\"\"\"\n",
      "\n",
      "def nk_format_matrix(M, precision=7):\n",
      "    pretty = lambda x: ' '.join(\n",
      "        map('{{:0.{}f}}'.format(precision).format, x))\n",
      "\n",
      "    nk = '{{{0}}}\\n'.format(pretty(M[0]))\n",
      "    nk += '\\t {{{0}}}\\n'.format(pretty(M[1]))\n",
      "    nk += '\\t {{{0}}}'.format(pretty(M[2]))\n",
      "    return nk\n",
      "\n",
      "COLOURSPACE = colour.sRGB_COLOURSPACE\n",
      "\n",
      "W_R_N = 'D65'\n",
      "W_T_N = 'D75'\n",
      "\n",
      "W_R = colour.ILLUMINANTS['cie_2_1931'][W_R_N]\n",
      "W_T = colour.ILLUMINANTS['cie_2_1931'][W_T_N]\n",
      "\n",
      "CAT = colour.chromatic_adaptation_matrix_VonKries(\n",
      "    colour.xy_to_XYZ(W_R),\n",
      "    colour.xy_to_XYZ(W_T),\n",
      "    transform='XYZ Scaling')\n",
      "\n",
      "M = np.dot(COLOURSPACE.XYZ_to_RGB_matrix,\n",
      "           np.dot(CAT, COLOURSPACE.RGB_to_XYZ_matrix))\n",
      "\n",
      "print(NUKE_TEMPLATE.format(nk_format_matrix(M),\n",
      "                           '{0}_to_{1}_ColorMatrix'.format(W_R_N, W_T_N)))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "    ColorMatrix {\n",
        "     inputs 0\n",
        "     matrix {\n",
        "         {0.9977895 -0.0083660 -0.0602694}\n",
        "\t {0.0003985 1.0008830 0.0051166}\n",
        "\t {0.0025633 0.0158961 1.1268520}\n",
        "       }\n",
        "     name D65_to_D75_ColorMatrix\n",
        "     selected true\n",
        "    }\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "CAT = colour.chromatic_adaptation_matrix_VonKries(\n",
      "    colour.xy_to_XYZ(W_R),\n",
      "    colour.xy_to_XYZ(W_T),\n",
      "    transform='CAT02')\n",
      "\n",
      "NPM_i = np.linalg.inv(colour.normalised_primary_matrix(\n",
      "    COLOURSPACE.primaries, W_T))\n",
      "\n",
      "M = np.dot(NPM_i,\n",
      "           np.dot(CAT, COLOURSPACE.RGB_to_XYZ_matrix))\n",
      "\n",
      "print(NUKE_TEMPLATE.format(nk_format_matrix(M),\n",
      "                           '{0}_to_{1}_NPM_ColorMatrix'.format(W_R_N, W_T_N)))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "    ColorMatrix {\n",
        "     inputs 0\n",
        "     matrix {\n",
        "         {1.0470997 -0.0433275 -0.0037723}\n",
        "\t {0.0020709 0.9978452 0.0000839}\n",
        "\t {0.0030194 0.0152122 0.9817683}\n",
        "       }\n",
        "     name D65_to_D75_NPM_ColorMatrix\n",
        "     selected true\n",
        "    }\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 2
    }
   ],
   "metadata": {}
  }
 ]
}