Output Transform Tone Scale

yeah, that’s true. @Thomas_Mansencal Hopefully I can develop a bit further…

I think OpenDRT is a work-in-progress experiment. The perceptual checkbox and saturation slider are indeed attempts of addressing the Abney and Hunt Effects. But I guess they are not necessarily meant to stay in the final version of OpenDRT (and rather go in a LMT) ?

But I guess this leads to the question of :

  • What would go in the Output transform itself ?
  • What would go in a “default” LMT ?

Jed did an interesting list already of the different modules in the Output Transform :

  • Input Conversion
  • Gamut Mapping
  • Whitepoint
  • Rendering Transform
  • Display Gamut Conversion
  • Inverse EOTF
  • Clamp

I’d be curious to know if everybody agrees with this list/structure. Furthermore you already listed some of the CAM “Effects” here (back in February ! Thanks for that !) :

Now that we have opened the can of worms, shall we talk about colour appearance modeling?

  • Surround/Viewing Conditions
  • Stevens Effect
  • Hunt Effect
  • Abney Effect
  • Bezold-Brücke Effect
  • And the remaining ones of Advanced Colorimetry

I have also read your answer about the Hunt Effect saturation slider and I thought it was really great ! I’d be of course quite interested if you have some kind of solution/hint for each of the “Effects”…

As you can you probably tell, I have a thing for listing stuff. It helps me to think. And hopefully it would help to see on which point the VWG agrees/disagrees (per-channel, chromaticity linear…) so we can keep moving forward.

Chris