add a srgb range/threshold to various effects

[geextahslex]

Expected behavior of the wanted feature

Hi, I would like to propose a handy feature to make various effects more tweakable by the user. Effects like glsl shader, lavfi filters, build in effects like saturation/brightness/contrast/gamma etc. I'm often face with this problem that I want to use a effect/filter but not on the entire image but on a specific range, like lows/highs/mids (0-255srgb).
There would need to be a smooth transition (smoothstep) between affected area and non affected, to no get a harsh line.
This would enhance our image quality and would open a door for more creative usage of effects. Add a new dimension of flexibility.

an example of what I'm actually talking about
lavfi denoise:
you don't need to apply the filter to the whole image. 90% of the noise is present in the lows 0-40srgb. Here I simulated this effect in photoshop. A better experience. You get rid of the noise in the lows but keep details in the mids, like the face etc.

normal image

denoised with atadenoise

atadenoise applied only to srgb 0-40

Thank you :)

Alternative behavior of the wanted feature

No response

Log File

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Sample Files

No response

[ruihe774]

For glsl shaders, you can implement this feature in the shader code easily.

For lavfi filters, I believe this features can be implemented with a lavfi filtergraph. Alternatively you can just use VapourSynth. There are many existing VapourSynth scripts that can perform splitted processing based on luma.

[llyyr]

As you've been told, this kind of thing is better implemented as a VS script or a shader. But if you really want to do this with a filtergraph you can probably use the colorkey filter to make the reds transparent then with an overlay filter, overlay a video with denoise applied to the whole thing

[geextahslex]

"easily" and "just use xyz" not every person is a coding prodigy. Here you can see how this stuff ends like, 8 months no answer.
https://www.reddit.com/r/mpv/comments/16w8vrg/mpv_and_vapoursynth_scripts/
I also don't want to install 55 other programs.

Thats why I made this feature-request, to have a native mpv solution and make this more accessible for everyone. Not rely on 3rd party stuff.