Colour 0.3.9, Colour - HDRI 0.1.2 and ACES! has been quiet for a while however, it does not mean nothing happened. Colour 0.3.9 and Colour - HDRI 0.1.2 were released today and last week, concluding a major collaborative effort, the ACES community addressed an important feedback paper to the Academy leadership.

Colour 0.3.9

This release introduces some significant spectral computations performance improvements and various new objects:

  • Spectral code optimisations resulting in increased computations performance:

    • colour.SpectralPowerDistribution and colour.TriSpectralPowerDistribution classes are now 6.5 times faster.

    • colour.colour_quality_scale definition is now 10.5 times faster.

    • colour.colour_rendering_index definition is now 13.1 times faster.

    • colour.uv_to_CCT_Ohno2013 definition is now 15.7 times faster.

  • Correlated colour temperature to chromaticity coordinates uv computation accordingly to Krystek (1985) method.

  • Support for Luo et al. (2006) CIECAM02 based uniform colourspaces and colour differences.

  • Support for Dolby ICTCP colourspace.

  • Support for Canon Log 2 and Canon Log 3 log curves.

  • colour.RGB_Colourspace class can now either use instantiation time transformations matrices or derived ones. Consequently, the following RGB colourspaces Normalised Primary Matrices were replaced with the literature ones: ACES Primaries 0, Adobe RGB (1998), ALEXA Wide Gamut RGB, CIE RGB, ROMM RGB, sRGB, V-Gamut. It introduces small computation discrepancies compared to Colour 0.3.8.

  • Implement support for Canon Log 2 and Canon Log 3 log curves.

  • Implement support for RedWideGamut RGB colourspace and Log3G10, Log3G12 log curves.

  • Implement support for ACEScct colourspace and ACEScct log curves.

Colour can now be installed from conda-forge:

conda install -c conda-forge colour-science

Visit the Colour's releases page for complete details.

Colour - HDRI 0.1.2

This release introduces some new capabilities:

  • Support for Adobe DNG SDK colour processing for improved white balancing.

  • Custom CIE LCHab highlights recovery definition.

Visit the Colour - HDRI's releases page for complete details.


Various members of the ACES community addressed a retrospective and enhancements document about ACES to the Academy leadership. It describes improvements that the system could implement to increase its adaptability and reach. It is the result of months of collaborative writing, years of discussions between expert users and summarizes decades of cumulated experience using the system.


  • Sean Cooper, Sony Pictures Imageworks

  • Thomas Mansencal, Wingnut Films Production Ltd.

  • Kevin Wheatley, Framestore


  • Remi Achard, Eclair

  • Steve Agland, Animal Logic

  • Haarm-Pieter Duiker, Duiker Research

  • Alex Fry, Animal Logic

  • Brian Karis, Epic Games

  • Sebastien Lagarde, Unity Technologies

  • Robert Molholm, Industrial Light and Magic

  • Michael Parsons, The Moving Picture Company

  • Nick Shaw, Antler Post


  • Lars Borg, Adobe

  • Alasdair Coull, Wingnut Films Production Ltd.

  • Marie Fetiveau, Rodeo FX

  • Lucien Fostier, Image Engine Design

  • Alex Fry, Electronic Arts

  • Thomas Hourdel, Unity Technologies

  • Anders Langlands, Weta Digital

  • Jasmin Patry, Sucker Punch

  • Troy James Sobotka, Freelancer

The document can be found at this URL: and the LaTex code is hosted on Github.


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