One thing very interesting, when I work in 100% mode, the picture looks sometimes a bit worse or at least not that pleasing, but when I zoom out to full view (finally relevant), suddenly you can see a big improvement in microcontrasts with the new NLM method
I just sometimes would like to have a wider range of the auto-sliders. Sometimes I have them at the end and still not totally happy
In my humble opinion, lowering opacity works well for low and medium ISO images, but less well in high ISO images.
In that case if you want grain, I would push central pixel weight, and reduce strength if needed.
I almost always use NLM, but I also always tweak its parameters, I find the default force value almost always too strong
Try doing the same approach (tweaking the 3 parameters instead of just reducing opacity) with the others images
Also, itâs not a big deal if some chroma noise remains at 100% zoom level, if you donât see it when zoomed out
Anyway, things I say are only advices, you can still use color blending modes if that suits your need.
You do have a wider range, for almost all parameters of denoise profiled
You can enter values outside visible bounds by keyboard. The real ranges are:
[0;12] for patch size
[1;30] for search radius
[0;20] for scattering (though the value 1 is probably enough even for very high ISO images, and you will probably destroy local contrast by pushing the value too far)
[0;10] for central pixel weight (though very large value makes the result very similar to having 0 in patch size)
Presets still have some interest IMHO, as they show examples on how to use wavelets curves, and some people like the results they have with them, so it makes sense not to deprecate them too early to give some time to people to change their habits if they want to I guess
@rawfiner, thanks for all your hard work on denoising. Iâve been getting excellent results with the NLM auto on my sports pictures taken at night. Sometimes I have to make a minor tweak, but most of the time itâs good.
I agree with keeping the presets. I still use the chroma preset when denoising low iso color noise or color noise introduced when I use some of @s7haboâs excellent editing techniques. I also think that a lot of work went into figuring out those curves, and it shouldnât be lost.
Finally, I think NLM auto makes easy denoising accessible to the masses.
Just checked this out and I must say I am impressed with the result⊠though its slower than old denoise.
A few spontaneous thoughts from a user: 1. I miss a slider for adjusting chroma denoise. 2. Do not remove the old presets please, they were introduced just 1 year ago I think. Old denoise is faster and useful when noise is not so strong. And some users like what they are used to. Though I admit it is somehow misleading.
In terms of quality/result similar, maybe a little bit better. In terms of speed, worse. But the math behind it seems to be different, and so the usage is different, too. I donât know. I still think RT is better in terms of sharpening/demoisaicing/noisereduction/resolution, but dt has other advantages. New denoise in dt is certainly much better than old denoise, especially with high iso shots. Overall new denoise is simlar to RT. If you want to use new denoise you should have GPU acceleration (OpenCL), otherwise it must be really slow.
Ok, thanks. Iâm using RawTherapee a lot, but if I encounter a high iso noisy image , I skip RT and do all my edit in DxO.
PRIME Noise reduction is also slow/very slow.
I find the âpreserve shadowsâ slider very useful. In darktable 2.6 I sometimes used a parametric mask to increase the denoise intensity in darker areas, the new features make that much easier.
In my experiences with the new profiled denoise the loss of detail is very low, the darker parts become a bit darker than before and you lose a bit of sharpness in the image. But you can easily compensate that.