Experiments with a scene-referred local contrast module - proof of concept

[Wilecoyote]

@Christian-B

I asked myself the same questions. Until now, I hadn’t dared to change your default settings, which work extremely well. You’re right: the two interfaces don’t necessarily have to share the same settings. We can keep your optimal values ‘hard-coded’ for the overall approach and use the sliders to adjust the intensity of each frequency.

Thank you for your throughout explanation!

I’ve made some updates to my version:
https://github.com/wilecoyote2015/darktable/releases/download/local_contrast_rgb_multiscale_0.2/Darktable-5.5.0+106.g488568219d-dirty-x86_64.AppImage

• I’ve decided to use a percentage for the detail boost parameter and renamed it to “detail strength” so that it is maybe a bit more intuitive that 100% means vanilla strength of the detail and 0% means it is muted. The primary reason to not chose [-1, …] scale is because although having 0 as neutral is beneficial, having -1 as bound for muted detail is counterintuitive, especially as the possible positive values can be almost arbitrarily high.
• There are now useful default feature scale values. Scale 2 still has default 150% detail strength because this provides a nice clarity-like effect that immediately pops out when activating the module.