Notice of Meeting - ACES Gamut Mapping VWG - Meeting #16 - 6/11/2020

Discussions - ACESNext VWG – Gamut Compression/Mapping
1

ACES Gamut Mapping VWG Meeting #16

Thursday, June 11, 2020
9:30am - 10:30am Pacific Time (UTC-4:30pm)

Please join us for the next meeting of this virtual working group (VWG). Future meeting dates for this month include:

  • 6/18/20 5pm
  • 6/25/20 9:30am

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2

Recap:

  • @joseph asked if the gamut mapping algorithm would be a required component of an ACES 2.x pipeline, @matthias.scharfenber proposed the “opt-out” scenario, which would cover the case of a ‘more accurate camera’ proposed by Joseph
  • @Alexander_Forsythe brought up that the documentation - both technical and user guides - will need to be robust. We hope that the need for end user documentation will be minimal, if the gamut mapper “just works”.
  • For invertibility - can we guarantee that all processing will be happening in float? No - but we should definitely encourage it, and most modern systems should already operate in full float.
  • @jedsmith brought up the different use cases for the algorithm - on set, VFX, and DI being the main three. Are there different needs in each place or are they equal?
    • Jed points out that having more parameterization options would be useful for VFX in particular, to tune based on input
    • @carolalynn points out that ACES is by design immutable, and we don’t have a way to track these parameters effectively
    • @KevinJW had a great example - sharing parameters with different vfx houses sharing shots would be a nightmare
  • Matthias mentioned that another potential use case for an “opt-out” non-gamut mapped transform would be to provide version compatibility between ACES 1.x and 2.x. Carol suggested later that “opt-out” should be referred to as the “legacy transform” instead.
  • Joseph - should we have a guide and versioning info for productions?
    • Carol - yes - ala VFX reference platform expanded, and CLF reference implementation example for DCCs etc
  • @nick demoed Baselight BLGs in Nuke of different camera output transforms applied to gamut mapped images - thinking is to use different display transforms to make sure we’re not overlapping scene-referred mapping issues with display referred ones
  • Overall, this call circled around use cases, and when/if the gamut mapping operation should be applied. Look forward to a new post summarizing Carol, Matthias and Nick’s thoughts on where we stand on this crucial juncture soon.