jedypod / gamut-compress Goto Github PK

Hello, I read the readme but I have a question... does this blinkscript or nuke gizmo match the same math as the official ACES 1.3 gamut compression?

In other words, I can use it in nuke to match my vfx pulls against some dailies that were generated by resolve 17 with ACES 1.3 gamut compression enabled?

Would be useful in general and for those of us without Nuke!

Thank you in advance for your work.

The latest version of 0.7 is not working in Windows 10 with Resolve 17 (17.1.1 Build 9) and ATI Radeon VII.

All previous releases are currently working to my system: 0.6 / 0.5 / 0.36 / 0.35 / 0.3.

Thank you.

Ted.

I'm not sure if this is a Rec709 only thing or not, but if I were to use your coefficients for any sample (ie. blue bar exr) blues skew to purple. I noticed this issue while working on an implementation in AviSynth.

The Nuke set up is a bit confusing but since you don't have an expressive code block to reference to I will post my implementation.

You seem to extract max() from columns in row-major order for the distance ratio matrix, while probably extracting rows is expected:

Max() for columns, yields [0.518208,0.074934,0.088542] for Rec709 from Rec2020:

max(DRat[0],DRat[3],DRat[6])
max(DRat[1],DRat[4],DRat[7])
max(DRat[2],DRat[5],DRat[8])

Max() for rows, yields [0.074934,0.518208,0.063425] for Rec709 from Rec2020:

max(DRat[0],DRat[1],DRat[2])
max(DRat[3],DRat[4],DRat[5])
max(DRat[6],DRat[7],DRat[8])

Another thing I implemented is distance aware thresholds, so the rolloff is equivalent for all the channels. If distance is short, you can get away with a lower threshold and hence keep more of the saturation. My function fit is: 0.085*log10(Dist+0.0036)+0.208

With that said I'm aware this is a workaround and the Path to White is skewed as this method only aligns primaries, so I still see, specially in red a big hue shift to oranges. This is not apparent with ACES ODTs because of its 'red glow' artifact though.

EDIT: By the way, I saw conflicting coefficients. In this post you recommended for ACEScg from AlexaWG [0.075553775,0.218766689,0.052656531] while in your current blink file you recommend [0.078,0.22,0.056]. With row max() I get [-0.007,0.0582,0.211105] including chromatic adaptation.

EDIT2: I noticed you didn't attach a license. Am I ok to port this to AviSynth+ or should I add a license disclaimer? Thanks!