“preserve luminosity” of “color balance” filter？

[TheTwo]

After some testing, I found out that “preserve luminosity” is actually “preserve lightness”.
This makes it difficult to use because HSL is too sensory to change.

I read some photoshop sources and found that their “preserve luminosity” is also not perfect (seems to be a compensation scheme)
In view of the algorithm difference between krita and ps (small range and large amplitude), I think it is more appropriate to directly use the “l” of lab.

[urzeye]

Yes, I agree with you. I think some of krita’s L is confused with HSL’s L

[EyeOdin]

There is a bunch of color web sites that especialized in color that do the same mistake so that would not surprise me if they were used as a resource when coding.