Ok, I haven't noticed such a limitation in the equalizer myself (although I don't generally use it for denoising). When I had difficulty removing noise with it however the problem I usually had was finding the right frequency for the noise not where I had anticipated it to be.
For some specific problems, such as applying heavy denoise where the background was fine vertical stripes (a reed bed) I did find some algorithms behaved much better than others but my knowledge is well out of date now. Since the arrival of profiled denoise and sensor improvements it has become a non-issue for me - up to stupidly high ISO values noise on a correctly exposed image just disappears without any special actions and in fact I automatically cut back the profiled denoise with a 50% blend before inspecting an image as it is for me a bit too strong. I haven't needed to use anything else for ages. Rob. -----Original Message----- From: Andy [mailto:[email protected]] Sent: 13 April 2017 14:07 To: Rob Z. Smith; darktable-users Subject: Re: [darktable-user] Can't remove high frequency chroma noise with equalizer I don't get great results with the de-noising modules. I can smooth over the noise with the wavelet denoising, but that also looses a lot of details. But I also just wanted to understand the equalizer. It seems I don't really understand what it does to the wavelets if I can't remove very high frequency noise. Maybe I should read the paper? But first I wanted to know if that was expected or if there was some easy explanation for it. On 04/13/2017 04:53 AM, Rob Z. Smith wrote: > Why would you want to use the equalizer? I mean, if you have a type of noise > that the dedicated de-noising modules are suitable for and more effective for > than the (more general purpose) equalizer, why not use them? > > Rob. > -----Original Message----- > From: Andy [mailto:[email protected]] > Sent: 13 April 2017 03:53 > To: darktable-users > Subject: [darktable-user] Can't remove high frequency chroma noise > with equalizer > > Hi. > I'm trying to understand the equalizer better. > I have an image shot at very high ISO: > https://www.dropbox.com/s/gkrcxshydk0slfc/DSC04403.ARW?dl=0 > I want to denoise it using the equalizer. > But no matter how high I drag the denoising curve, there is still high > frequency noise in the image: > https://www.dropbox.com/s/r7rxhgkzapdz72e/chroma_noise.png?dl=0 > > Is that expected? I would have thought that I can completely remove this > noise. > Using the profiled denoising with wavelets, I can easily smooth over it. > I thought > the equalizer could do the same. > > I'm using 2.2.4 > > Thanks! > > Andy > ______________________________________________________________________ > ______ > darktable user mailing list > to unsubscribe send a mail to > [email protected] > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to [email protected]
