3D-PRO - About Rendering Engines Colourspaces Agnosticism

about_rendering_engines_colourspaces_agnosticism.py

import numpy as np
import colour
from colour.utilities.verbose import message_box

name, data, illuminant = colour.COLOURCHECKERS['ColorChecker 2005']

sRGB_w = colour.sRGB_COLOURSPACE.whitepoint
sRGB_XYZ_to_RGB = colour.sRGB_COLOURSPACE.to_RGB
sRGB_RGB_to_XYZ = colour.sRGB_COLOURSPACE.to_XYZ
adobe98_w = colour.ADOBE_RGB_1998_COLOURSPACE.whitepoint
adobe98_XYZ_to_RGB = colour.ADOBE_RGB_1998_COLOURSPACE.to_RGB
adobe98_RGB_to_XYZ = colour.ADOBE_RGB_1998_COLOURSPACE.to_XYZ

# Preparing *dark skin* colour in various colourspaces.
index, name, x, y, Y = data[0]
XYZ_r1 = colour.xyY_to_XYZ((x, y, Y))

# *sRGB* colourspace 0-255 values with OETF applied.
sRGB_rd1 = colour.XYZ_to_sRGB(XYZ_r1, illuminant)

# *sRGB* colourspace linear values.
sRGB_r1 = colour.XYZ_to_RGB(XYZ_r1,
                            illuminant,
                            sRGB_w,
                            sRGB_XYZ_to_RGB)

# *Adobe RGB 1998* colourspace linear values.
adobe98_r1 = colour.XYZ_to_RGB(XYZ_r1,
                               illuminant,
                               adobe98_w,
                               adobe98_XYZ_to_RGB)

message_box(('Reference "dark skin" "CIE XYZ" colourspace tristimulus '
             'values:\n'
             '\n\t{0}\n'
             '"sRGB" colourspace values (OETF):\n'
             '\n\t{1}\n'
             '"sRGB" and "Adobe RGB 1998" colourspaces (Linear):\n'
             '\n\tsRGB: {2}\n\tAdobe RGB 1998: {3}').format(
    XYZ_r1,
    np.around(sRGB_rd1 * 255),
    sRGB_r1,
    adobe98_r1))

# Preparing *green* colour in various colourspaces.
index, name, x, y, Y = data[13]
XYZ_r2 = colour.xyY_to_XYZ((x, y, Y))

# *sRGB* colourspace 0-255 values with OETF applied.
sRGB_rd2 = colour.XYZ_to_sRGB(XYZ_r2, illuminant)

# *sRGB* colourspace linear values.
sRGB_r2 = colour.XYZ_to_RGB(XYZ_r2,
                            illuminant,
                            sRGB_w,
                            sRGB_XYZ_to_RGB)

# *Adobe RGB 1998* colourspace linear values.
adobe98_r2 = colour.XYZ_to_RGB(XYZ_r2,
                               illuminant,
                               adobe98_w,
                               adobe98_XYZ_to_RGB)

message_box(('Reference "green" "CIE XYZ" colourspace tristimulus '
             'values:\n'
             '\n\t{0}\n'
             '"sRGB" colourspace values (OETF):\n'
             '\n\t{1}\n'
             '"sRGB" and "Adobe RGB 1998" colourspaces (Linear):\n'
             '\n\tsRGB: {2}\n\tAdobe RGB 1998: {3}').format(
    XYZ_r2,
    np.around(sRGB_rd2 * 255),
    sRGB_r2,
    adobe98_r2))
XYZ_sRGB1 = colour.RGB_to_XYZ(sRGB_r1,
                              sRGB_w,
                              illuminant,
                              sRGB_RGB_to_XYZ)

XYZ_adobe981 = colour.RGB_to_XYZ(adobe98_r1,
                                 adobe98_w,
                                 illuminant,
                                 adobe98_RGB_to_XYZ)

message_box(('Converting back "dark skin" "CIE XYZ" colourspace '
             'tristimulus values from "sRGB" and "Adobe RGB 1998" '
             'colourspaces:\n'
             '\n\tFrom sRGB: {0}\n\tFrom Adobe RGB 1998: {1}\n'
             '\nEverything looks fine!').format(
    XYZ_sRGB1, XYZ_adobe981))
sRGB_m = sRGB_r1 * sRGB_r2 * sRGB_r2 * sRGB_r2 * 1000
adobe98_m = adobe98_r1 * adobe98_r2 * adobe98_r2 * adobe98_r2 * 1000

XYZ_sRGB_m1 = colour.RGB_to_XYZ(sRGB_m,
                                sRGB_w,
                                illuminant,
                                sRGB_RGB_to_XYZ)

XYZ_adobe98_m1 = colour.RGB_to_XYZ(adobe98_m,
                                   adobe98_w,
                                   illuminant,
                                   adobe98_RGB_to_XYZ)

message_box(('Multiplying "dark skin" with "green" and converting back to '
             '"CIE XYZ" colourspace tristimulus values from "sRGB" and '
             '"Adobe RGB 1998" colourspaces:\n'
             '\n\tFrom sRGB: {0}\n\tFrom Adobe RGB 1998: {1}\n'
             '\nHouston? We have a problem!').format(
    XYZ_sRGB_m1, XYZ_adobe98_m1))

output.txt

ssh://vagrant@127.0.0.1:2222/home/vagrant/anaconda/envs/python2.7/bin/python -u /colour-science/colour/colour/examples/ramblings.py
===============================================================================
*                                                                             *
*   Reference "dark skin" "CIE XYZ" colourspace tristimulus values:           *
*                                                                             *
*           [ 0.11518475  0.1008      0.05089373]                             *
*   "sRGB" colourspace values (OETF):                                         *
*                                                                             *
*           [ 115.   81.   68.]                                               *
*   "sRGB" and "Adobe RGB 1998" colourspaces (Linear):                        *
*                                                                             *
*           sRGB: [ 0.172906    0.08205715  0.05711951]                       *
*           Adobe RGB 1998: [ 0.14702493  0.08205715  0.05814617]             *
*                                                                             *
===============================================================================
===============================================================================
*                                                                             *
*   Reference "green" "CIE XYZ" colourspace tristimulus values:               *
*                                                                             *
*           [ 0.14985004  0.2318      0.07900179]                             *
*   "sRGB" colourspace values (OETF):                                         *
*                                                                             *
*           [  66.  149.   76.]                                               *
*   "sRGB" and "Adobe RGB 1998" colourspaces (Linear):                        *
*                                                                             *
*           sRGB: [ 0.05440562  0.29876767  0.07183236]                       *
*           Adobe RGB 1998: [ 0.12401962  0.29876767  0.08117514]             *
*                                                                             *
===============================================================================
===============================================================================
*                                                                             *
*   Converting back "dark skin" "CIE XYZ" colourspace tristimulus values      *
*   from "sRGB" and "Adobe RGB 1998" colourspaces:                            *
*                                                                             *
*           From sRGB: [ 0.11518475  0.1008      0.05089373]                  *
*           From Adobe RGB 1998: [ 0.11518475  0.1008      0.05089373]        *
*                                                                             *
*   Everything looks fine!                                                    *
*                                                                             *
===============================================================================
===============================================================================
*                                                                             *
*   Multiplying "dark skin" with "blue" and converting back to "CIE XYZ"      *
*   colourspace tristimulus values from "sRGB" and "Adobe RGB 1998"           *
*   colourspaces:                                                             *
*                                                                             *
*           From sRGB: [ 0.86538968  1.58721208  0.20819516]                  *
*           From Adobe RGB 1998: [ 0.63283056  1.47002564  0.14148678]        *
*                                                                             *
*   Houston? We have a problem!                                               *
*                                                                             *
===============================================================================

Process finished with exit code 0