Help with denoise (profiled) in Darktable 3.0

[emem (Mikael)]

Hi
I’m running Darktable 3.0.0 on Manjaro Linux. I’m would like some tips on how to get better result with the new denoise (profiled) module for this picture. I took this picture at sunrise and exposed for the highlights. As you can see I increased the exposure on the shadows a lot in post-production but without over-exposing the sky. Filmic RGB is fantastic!

But I’m struggling with reducing the chroma noise on the subjects clothes and on the black areas of the pram. I don’t mind if the chroma noise is turned into luma noise, as long as the denoising blur the details too much.

Promenad i gryningen-0001.NEF.xmp (9.9 KB) Promenad i gryningen-0001.NEF (24.4 MB)

I read the description of the new version of the denoise (profile) module, but still failed.

[KristijanZic]

Do this for color noise:

Do this for luma noise:

Tweak it a bit to fit your noise level if you need to.

[Thomas_Do (Thomas)]

I think you pushed the reds a little to far . Try denoise (bilateral filter) for the red channel.

Promenad i gryningen-0001.NEF.xmp (10.8 KB)

[rawfiner]

I have done a video tutorial about recent changes and how I denoise pictures here:

Noise reduction with darktable 3.0

Maybe it will help!

[emem (Mikael)]

Thanks! That produced the best result of all the tips. But, dear me! Bilateral filter is a slooow module.

[emem (Mikael)]

Thanks, I will check out that video.

[rawfiner]

Bilateral filter becomes faster if you use a big radius

[Thomas_Do (Thomas)]

@emem

But, dear me! Bilateral filter is a slooow module.

Do you use OpenCL acceleration?

[emem (Mikael)]

@Thomas_Do: Yes, with a GTX 970.

[Thomas_Do (Thomas)]

Yes, the module is calculation-intensive. It may be best to do the denoising after the rest is finished .

[emem (Mikael)]

That’s what I usually do with denoising…