From last meeting notes:
- Pekka Riikonen: I’ll open a PR with a tweaked version that makes the lines less curvy.
I’ve been unable to get it to a point where there isn’t some issue and I am hesitant making a new version that isn’t an improvement. It seems that if we want to lessen the skew to purple then the blue will always be dark (think blue patch in ColorChecker getting darker, or the example pictures above). With brighter blue the skew either always happens, or if it’s “fixed” then other issues come up, like the gamut mapping result around cyan/blue that has been discussed before gets worse. I can see the same happening with the old compression as well by changing primaries. It seems we’ve made this skew worse in our effort to have brighter blue. There may be a compromise that is good enough, but not without darker blue. But why is the blue so dark in this model? Perhaps the lightness metric for blues could be changed, somehow? BTW, making the blue brighter in LMT works fine without introducing any skew to purple (with the above experimental version).