local adjustments & highlight recovery

Dear All,

I am having problems with local adjustments and highlight recovery.

When I have local adjustments (light and colors) in an areas where highlightss were recovered, even if the mask does not apply to this area, the highlight recovery is gone, and over-exposed areas re-appear.

Have anybody a method to avoid this? I am doing something incorrect?

Introducing a second filter to reduce lightness or contrast, is only a partial solution. If the recovery was significant, this will create a grey area, since this second correction is applied in a blown area.

Any help is very wellcome!

You could try the following:

*Activate “Show additional settings” and then “Specific cases”
*Change the default option in the “Avoid color shift” drop-down menu from “XYZ Absolute” to “Munsell only”

There’s another thread about this: Local adjustments - Color appearance (and log) are incompatible with highlight correction?

@hanay1978 @Wayne_Sutton @Lawrence37

For some time now, probably because users are using “Local adjustments”, “Highlight” or “gamut” problems have appeared.

But these behaviors seemed a bit random. Images with highlights required acting differently than what @Wayne_Sutton highlighted above:
*Activate “Show additional settings” and then “Specific cases”
*Change the default option in the “Avoid color shift” drop-down menu from “XYZ Absolute” to “Munsell only”

But in other cases as shown by @Lawrence37 it was the opposite that had to be done. Last RT 5.10 is by default with the latter choice.

This weird behavior intrigued me and I searched the code to see what could be causing this. I discovered that in certain places I “clip” the luminance and/or color components. I brought a remedy which I explain here

https://discuss.pixls.us/t/another-tutorial-color-appearance-truck-under-a-tunnel/41947/17

This change is only in the “lacam16n” branch which made it possible to test it.

I’m going to do a Pull-Request (PR) with only this change (clip, and GUI), in order to modify Dev.

Jacques

1 Like

Hello

I just create the Pull-request here :

https://github.com/Beep6581/RawTherapee/pull/6965

This PR

  • set default value (new spot) to “Munsell only”
  • change behavior in “Local Adjustments” when the algorithm finds a “clip” function (Luminance, chroma…)
  • mark in pp3 if the value is set (5.10) to “XYZ absolute” and switch to “Munsell only”

Branch : “la_gamutmunsell”

The executables are being developed and should appear in pre-dev builds (at least I hope) - with “la_gamumunsell” in the title.
https://github.com/Beep6581/RawTherapee/releases/tag/pre-dev-github-actions

Jacques