[Feature Request] General Dimming

[AeliusSaionji]

Confirmation

• [x] I have read the Code of Conduct
• [x] I have searched the existing issues

Feature Description

Brightness/contrast controls change the gamma (as they should), but there's no easy way to apply a gamma-neutral dimming effect.

Describe the Solution

Perhaps the easiest solution is to add a padlock icon next to the RGB color scale sliders- when active, all three sliders move together to apply dimming without color change.

Describe Alternatives

Alternatively

• this could be an additional slider adjustment
• the toggle could replace the RGB sliders with a single slider

Additional Context

Thanks!

Sufficiency Confirmation

• [x] I have provided all the information requested above and deemed sufficient for the developer to address the issue

[Hamza417]

Brightness slider almost have the same effect, but I had to do brightness adjustment relative to contrast since adjusting them separately produced unwanted results. I don't exactly remember why I chose to do it this way. A general dimming should be more like applying a black overlay and changing the alpha of the black layer?

Something like this?

https://github.com/user-attachments/assets/493863e1-206b-4a11-bd8e-56dd4e32097a

[AeliusSaionji]

A general dimming should be more like applying a black overlay and changing the alpha of the black layer?

Yes, that sounds right.

Brightness/Contrast, as I understand them, are respectively shifting the black level and white level, which influences the gamma curve of the image. Afaik, to preserve gamma, you'd want to adjust both at the same time by the same amount. The brightness/contrast sliders as implemented don't really allow for eyeballing this. However, the rgb sliders do, as best I can tell. They can all be set to roughly 50% to dim by 50%.

I did some cursory googling (https://www.cambridgeincolour.com/tutorials/histograms2.htm) and there might technically be a difference between applying the dimming via rgb channels vs luminance, but playing in Snapseed I can't visually see any difference when simply lowering the ceiling.

I'm sure having these individual controls is desirable for artistic effect, but I'm personally just looking to separate my background from the launcher UI in a neutral way.

Thanks again