OpenColorIO

Open Source Color Management

OpenColorIO 1.1.1 documentation

aces_1.0.3

ACES 1.0.3 OpenColorIO configuration

Information about ACES

The ACES project home page is here:

The latest documentation on the ACES transforms and specifications can be found here:

Colorspaces

Colorspaces in this configurations are grouped into the following families: ACES, ADX, Look, Output, Input, Utility, Aliases. Descriptions for the colorspaces in the different families are provided below.

For ease of use across a broader number of applications, the family name of each colorspace is pre-pended to the colorspace name when the configuration is authored. Those prefixes will be omitted in this document, but will show up when the configuration is loaded and used.

ACES Colorspaces

  • ACES2065-1
  • ACEScc
  • ACEScct
  • ACESproxy
  • ACEScg

Description

Colorspaces and transforms representing the core ACES working and interchange colorspaces.

Technical information

Transforms generated based on the ACES CTL Transforms

Output Colorspaces

  • sRGB
  • sRGB (D60 sim.)
  • Rec.709
  • Rec.709 (D60 sim.)
  • Rec.2020
  • Rec.2020 ST2048 (1000 nits)
  • DCDM (P3 gamut clip)
  • DCDM
  • P3-D60 ST2048 (1000 nits)
  • P3-D60 ST2048 (2000 nits)
  • P3-D60 ST2048 (4000 nits)
  • P3-D60
  • P3-DCI

Description

Colorspaces and transforms implementing the ACES Output Transforms. These colorspaces produce code values ready for display on hardware devices calibrated to the standard used to name the colorspace.

Technical information

  • Transforms generated based on the ACES CTL Transforms
  • All transforms produce full-range output. Host applications should be used to apply an full-to-legal scaling needed.

Input Colorspaces

There are a variety of Input Transforms covering different cameras manufacturers, gamuts, transfer functions and camera settings. See below for specifics.

Description

Colorspaces and transforms that implement the ACES Input Transforms. These colorspaces are used to convert from camera-specific formats and encodings to ACES.

Technical information

References and descriptions are provided for each group of Input Transforms below. - The colorspaces whose names include a transfer function and a gamut name are full implementations of ACES Input Transforms.

  • Ex. The ARRI ‘V3 LogC (EI160) - Wide Gamut’ colorspace
  • Ex. The RED ‘REDlogFilm - DRAGONcolor2’ colorspace
  • Ex. The Canon ‘Canon-Log - DCI-P3 Daylight’ colorspace
  • The colorspaces that start with ‘Linear - ‘ will convert to or from a specific gamut but not apply a transfer function.
  • The colorspaces that start with ‘Curve - ‘ will apply a transfer function but not convert between gamuts.

ADX Colorspaces

  • ADX10
  • ADX16

Description

Colorspaces and transforms representing the ACES ADX spaces used for film scanning and printing.

Technical information

ARRI

Canon

RED

GoPro (Experimental)

  • The quality and consistency of these transforms has not been verified.
  • Conversations with David Newman of GoPro

Utility

Description

A collection of colorspaces that are used to facilitate the creation of LUTs and other basic functionality.

Technical information

  • The ‘Log2 xx nits Shaper’ and ‘Dolby PQ xx nits Shaper’ spaces cover the linear range centered around 18% grey. The 48 nits spaces cover -6.5 stops (0.0028125) to +6.5 stops(16.291740). The 1000 nits spaces cover -12 stops to +10 stops. The 2000 nits spaces cover -12 stops to +11 stops. The 4000 nits spaces cover -12 stops to +12 stops.
  • The LMT shaper spaces cover the linear range going from 10 stops below 18% grey (0.00017578125) to 6.5 stops above 18% grey (16.291740)
  • The colorspaces starting with ‘Linear - ‘ will convert to or from a specific gamut but not apply a transfer function.
  • The colorspaces starting with ‘Curve - ‘ will apply a transfer function but not convert between gamuts.

Look

Colorspaces

  • ACES 1.0 to 0.1 emulation
  • ACES 1.0 to 0.2 emulation
  • ACES 1.0 to 0.7 emulation

Description

Colorspaces and transforms emulating the look of the ACES 0.1, 0.2 and 0.7 release.

  • Should be applied to data in the ACES2065-1 colorspace.
  • Should be used before an ACES Output Transform.

Technical information

Transforms generated based on the ACES CTL Transforms

Roles

Description

The role colorspaces are aliases to the colorspaces used for the OCIO ‘roles’ functionality.

Aliases

Description

The alias colorspaces are named with all lower-case letters and no spaces, dashes, parentheses or other characters that would not work well in a filename. They are only references, aliases for the base colorspaces with more user-friendly names. These spaces were added to enable OCIO’s token-based colorspace / filename matching.

  • These colorspaces should not generally be used by most artists.

Roles

The standard OCIO roles are defined. They role assignments are:

  • color_picking: Output - Rec.709
  • color_timing: ACEScc
  • compositing_log: ADX10
  • data: Raw
  • default: ACES2065-1
  • matte_paint: ACEScc
  • reference: Raw
  • scene_linear: ACEScg
  • texture_paint: Raw

Additionally, a number of colorspaces that are gaining wider adoption have been added to the config. Their names and assignment are:

  • compositing_linear:: ACEScg
  • rendering:: ACEScg

Displays and Views

The default config has one Display named ACES, which contains the following Views / colorspaces:

  • sRGB, colorspace: sRGB
  • sRGB D60 sim., colorspace: sRGB (D60 sim.)
  • DCDM, colorspace: DCDM
  • DCDM P3 gamut clip, colorspace: DCDM (P3 gamut clip)
  • P3-D60, colorspace: P3-D60
  • P3-D60 PQ 1000 nits, colorspace: P3-D60 PQ (1000 nits)
  • P3-D60 PQ 2000 nits, colorspace: P3-D60 PQ (2000 nits)
  • P3-D60 PQ 4000 nits, colorspace: P3-D60 PQ (4000 nits)
  • P3-DCI, colorspace: P3-DCI
  • Rec.2020, colorspace: Rec.2020
  • Rec.2020 ST2048 1000 nits, colorspace: Rec.2020 ST2048 (1000 nits)
  • Rec.709, colorspace: Rec.709
  • Rec.709 D60 sim., colorspace: Rec.709 (D60 sim.)
  • Raw, colorspace: Raw
  • Log, colorspace: ACEScc

Considerations for custom config generation:

  • The choice of a single Display and many Views may not align well with the implementation of OCIO in an application.
    • If you would like to generate a config that contains multiple Displays, with a small number of Views for each, review the config generation script’s ‘–createMultipleDisplays’ option.
  • If a Look is added to the config, a new set of Views will be added, one for each of the Views listed above except Raw and Log, that includes the Look. The Views with Looks will be interleaved in the View list with the original Views.
    • To add a custom Look to the config, review the config generation script’s ‘–addACESLookLUT’, ‘–addACESLookCDL’, ‘–addCustomLookLUT’ and ‘–addCustomLookCDL’ options.

LUTs

The default resolution is 65x65x65 for the 3D LUTs and 4096 for the 1D LUTs.

OCIO LUTs The LUTs used internally by OCIO can be can be retrieved from the repository here.

Baked LUTs LUTs that can be used outside of OCIO are included in the ‘baked’ directory here.

  • The LUTs encode the ACES Output Transform for a specific colorspace input and are generally named:
    • ‘Ouput Transform name’ for ‘Input colorspace name’.extension
    • Ex. ‘sRGB (D60 sim.) for ACEScc.icc’

The LUTs included in the ‘baked’ directory cover the following formats and applications:

  • .3dl for Autodesk Flame
  • .3dl for Autodesk Lustre
  • .lut for SideFX Houdini
  • .csp for Autodesk Maya
  • .icc for Adobe Photoshop

Generating Configurations

Python Configurations can be generated by the following Python package: aces_1.0.3/python

Usage is described on the command line and in the package root __init__.py file.

Features exposed for customization by the user include:

  • The resolution of 1D and 3D LUTs
  • Inclusion of custom Looks
  • Two modes of creating the list of OCIO Displays and Views
  • Selection of shaper function: Log2 or Dolby PQ

CTL Source The configuration depends on the ACES 1.0.3 release. The release contains a number of file renames and the new ACEScct color space and a number of minor bug fixes and small additions, but is otherwise very similar as the master ACES 1.0.2 release.

The CTL is available here:

Clone this repo using the following command:

Dependencies

The Python configuration generation package depends on the following libraries:

Building on macOS - Use the following commands to build these packages on macOS

  • OpenColorIO
    • brew install -vd opencolorio –with-python
  • Update the homebrew repository of install scripts to make sure that OpenImageIO is included.
    • brew tap homebrew/science
  • Optional Dependencies for OpenImageIO
    • brew install -vd libRaw
    • brew install -vd OpenCV
  • OpenImageIO
    • brew install -vd openimageio –with-python
  • CTL
    • brew install -vd CTL
  • OpenColorIO, a second time. ociolutimage will build with openimageio installed.
    • brew uninstall -vd opencolorio
    • brew install -vd opencolorio –with-python

Thanks

The script used to generate these transforms and the transforms themselves were the product of work and conversations with a number of people. Thanks go to:

  • Steve Agland
  • Joe Bogacz
  • Jack Binks
  • Scott Dyer
  • Alex Fry
  • Alex Forsythe
  • Joseph Goldstone
  • Stephen Hill
  • Jim Houston
  • Thomas Mansencal
  • Robert Molholm
  • Nikola Milosevic
  • Will McCown
  • Graeme Nattress
  • David Newman
  • Sam Richards
  • Erik Strauss
  • Doug Walker
  • Kevin Wheatley

Author

The original author of this OCIO config is:

  • Haarm-Pieter Duiker

© Copyright Contributors to the OpenColorIO Project. Created using Sphinx 1.2b3.