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AcademySoftwareFoundation / OpenTimelineIO

Open Source API and interchange format for editorial timeline information.
http://opentimeline.io
Apache License 2.0
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Model color space expression in OTIO (e.x. Rec. 709, ACES Linear, Rec. 2020, etc.) #857

Open reinecke opened 3 years ago

reinecke commented 3 years ago

In image pipelines it can be useful to know the intended colorspace of a timeline as well as the media composed into that timeline when trying to either re-create a "look" or find out what someone earlier in the pipeline may have been using in their work context (often to try and locate mismatches). OTIO should have a way to describe colorspaces used in certain contexts.

reinecke commented 1 month ago

There's a high-level decision I think we have to make about modeling the color pipeline through the timeline heirarchy where we select from two different approaches:

  1. Declare the colorspaces at the MediaReference, Clip, and Timeline level and allow some system (like OpenColorIO) to discover how to go from one to the next via some out-of-scope to OTIO ruleset
  2. Follow the ACES AMF model which explicitly describes color in terms of what transform to use
meshula commented 1 month ago

Do we want to introduce ACES AMF into an environment where we are strongly centralized around OCIO, and now OCIO/NanoColor? If we don't get it "for free" from OCIO, I'm very hesitant.

My recommendation:

  1. Start by raising the topic at the ASWF Color Interop forum https://wiki.aswf.io/display/CIF/Color+Interop+Forum+Home and gather some opinions.

  2. There should be an analysis of color transforms and how they fit in an editorial composition. See the nanocolor transformation charts for an example.

  3. There should be an examination of where color space transformations actually exist in NLEs. I have a strong suspicion that the granularity proposed here is not accommodated in general.