Denoise in Darktable is not as good as I hoped

Tranzistors · 08-04-2018, 12:04 AM

It is a well known truth that RAW files have less noise than JPEGs, except for me don't. When shooting at iso 6400 my K-1 does a pretty good job of reducing color noise and there is some fuzziness around edges. When I open the RAW version in Darktable, it has some serious light show going on. All the denoising strategies I could find were either too aggressive or even gave details that were just not there. To give a better idea of what I mean, I made an experiment.

The first two images are at ISO 100 to give a baseline. The denoise was up to the maximal available level or until the light noise was gone (the module used is in the description of the images). None of the results came anywhere near what the camera could do so either I am really really bad at this or Darktable is really bad at this. I might consider moving to RawTherapee. Lightroom is not even considered since I'd rather upgrade to K-1ii, which is has much more manageable color noise than my K-1, that is to say that applying default profiled denoise it gets rid of the already minimal color noise and doesn't destroy details.

LensBeginner · 08-04-2018, 12:53 AM

Uh... actually thr opposite is true... RAW files generally have more noise than JPEG files, since they haven't gone through the noise reduction algorithms in camera.
It's up to you to do the NR and find your ideal balance between noise reduction and detail preservation, something you can't do very effectively with JPEGs because compression artifacts get in the way.
Not familiar with Darktable, but you could try the Google Nik collection of plugins (you'll need a host software), which has a pretty good (and free) noise reduction module.

house · 08-04-2018, 02:03 AM

I can't see your files due to flickr sign in required. There are many ways to denoise in Darktable and you can always tune the behaviour to your liking.
This one is quite processing intensive but quite good
Darktable Tricks - Processing - discuss.pixls.us

Originally posted by asn at pixls.us:

The denoise triple

denoise (profiled) instance 0; wavelet; strength 1; opacity: 100%; blend mode: color
denoise (profiled) instance 1; wavelet; strength 1; opacity: 50%; blend mode: lightness
denoise (profiled) instance 2; non-local means; strength 1; opacity: 30%; blend mode: averaging

I’ve created presets for those which I called (instance 0, instance 1, instance2).

Follow the link above and there are other suggestions in the thread.

Tranzistors · 08-04-2018, 02:10 AM

Originally posted by LensBeginner

Uh... actually thr opposite is true... RAW files generally have more noise than JPEG files, since they haven't gone through the noise reduction algorithms in camera.
It's up to you to do the NR and find your ideal balance between noise reduction and detail preservation, something you can't do very effectively with JPEGs because compression artifacts get in the way.
Not familiar with Darktable, but you could try the Google Nik collection of plugins (you'll need a host software), which has a pretty good (and free) noise reduction module.

I understand that RAWs will be nosier before I do any noise reduction. All I want is to be able to at least replicate the noise reduction that my camera is capable of.

parinya-ekparinya · 08-04-2018, 03:39 AM

I use darktable for more than a year. Using this software is not straightforward. I would say there are so many things you could do (and should do) for noise reduction. For example, instead of using only one denoise profile, darktable usually gives you a better result if you use two denoise profiles with different blend modes: one for chroma noise and another for luma noise. You could even go further with bilateral filter and equalizer for noise reduction, but that requires time to tweak things.

Nowadays, I mostly rely on DxO Optics Pro for noise reduction. :-)

**BigMackCam** · 08-04-2018, 03:47 AM - **3 Likes**

I thought the same as you when I first started using Darktable, but in fact it has incredibly powerful noise reduction - to the point where I now far prefer it over Lightroom, primarily because of the range of tools and fine control it provides, along with retention of detail (if you use the tools properly). But it takes some learning to understand how everything works.

The first thing you need to do is select an appropriate demosaicing algorithm for your photos. By default, Darktable applies "PPG (fast)", which allows for fast on-screen rendering, but results in a noisier appearance. My favourite is VNG with five times colour smoothing, but many prefer AMaZE. VNG produces a smoother result, AMaZE produces a perceptually-more-detailed result (but with maze artefacts that I don't personally like).

With your demosaicing sorted out, there are several Darktable tools you can use to reduce both colour and luminance noise. I prefer the Equalizer tool for both (using separate instances of the tool - one blended uniformly for colour, the other for lightness), but there's a bit of a learning curve involved - it requires some trial and error and practice.

If you're shooting really high ISO images, the Equalizer won't get rid of all colour noise, but gentle use of the Denoise (bilateral filter) - radius 30, 0.050 for the red, green and blue channels (blended uniformly for colour) will usually eradicate the rest of it. I don't like to use the bilateral denoise on its own for colour noise reduction - I only ever use it in tandem with the Equalizer.

Finally, be sure to adjust the threshold in the Sharpening tool, as it will sharpen remaining noise if you leave it set at the default setting of 0.500. I adjust it on an image-by-image basis, but typically start with a setting of 1.200. This ensures that edges are sharpened, but minimises sharpening of noise.

**twilhelm** · 08-04-2018, 04:38 AM

Mike did a great job explaining Darktable. I’d like to emphasize learning to use the equalizer, especially multiple instances of it.

On another note, Rawtherapee is also very good, especially with AMaZE. A good starting point would be to read squirrelmafia’s thread on Rawtherapee. He spent a lot of time creating presets for high ISO photos.

MaineNative · 08-04-2018, 04:51 AM

I have used Noiseware as a plug-in to Photoshop, but I think it can run stand-alone. It has different selections for standard noise reduction, strong noise reduction, portraits, landscapes or night shots. The choices adjust the noise removal and detail protection very well IMO.

Roadboat24 · 08-04-2018, 06:50 AM

I also use Darktable and as others have said, there is a learning curve. If I'm impatient I also use Noiseware Standard Edition. It's fast, easy, uncomplicated and does a pretty fair job.

Tranzistors · 08-04-2018, 10:47 AM - **1 Like**

Originally posted by BigMackCam

Finally, be sure to adjust the threshold in the Sharpening tool

THIS. I had “sharpen” auto-applied to all my images (seems like default Darktable behavior). When I removed it, suddenly all suggested denoising strategies became usable. Thank you for restoring my sanity.

Originally posted by house

This one is quite processing intensive but quite good
Darktable Tricks - Processing - discuss.pixls.us

This IS good. I guess I'll lose a couple of hours trying stuff out.

Originally posted by twilhelm

On another note, Rawtherapee is also very good

I plan to look into it. Darktable has tethering (and I hope it will support K-1), but RawTerapee is written in C++ and gtkmm, which I prefer over C and GTK+ (if I ever get to contribute to any of those projects, that might become relevant).

**BigMackCam** · 08-04-2018, 11:06 AM

Originally posted by Tranzistors

THIS. I had “sharpen” auto-applied to all my images (seems like default Darktable behavior). When I removed it, suddenly all suggested denoising strategies became usable. Thank you for restoring my sanity.

You're very welcome. In the beginning, That was one of several things that tripped me up too

**Mikesul** · 08-04-2018, 02:19 PM

I have not used DarkTable but this thread has been encouraging in that is demonstrated that seemingly complex problems with unfamiliar software can have easy fixes. I may give it a whirl.

Excalibor · 08-12-2018, 09:51 AM

Sorry to wake up an old thread, but i don't think my doubt merits a new thread.

Some of you mentioned that you changed the demosaicing algorithm and took the automatic sharpening away...

Where in the config can I change these things?

I have had quite satisfactory results sliminating noise and haze with Darktable, by using denoise and also by playing with the color channels, but the proposed solutions really look like an improvement... I don't usually mind luma noise, I might even enhance it and switch to black&white; plus my K-3 has a very nice noise, if that make sense: but chroma noise is definitely a nuisanse, and the loss of sharp edges is very annoying, specially on high ISO wildlife pictures, which usually need some added cropping (robins are really small!!!).

Thanks in advance! :-)

**BigMackCam** · 08-12-2018, 12:09 PM

Originally posted by Excalibor

Some of you mentioned that you changed the demosaicing algorithm and took the automatic sharpening away...

Where in the config can I change these things?

The demosaic tool is in the "basic group", here:

... while the sharpen tool is in the "correction group", here:

Originally posted by Excalibor

I have had quite satisfactory results sliminating noise and haze with Darktable, by using denoise and also by playing with the color channels, but the proposed solutions really look like an improvement... I don't usually mind luma noise, I might even enhance it and switch to black&white; plus my K-3 has a very nice noise, if that make sense: but chroma noise is definitely a nuisanse, and the loss of sharp edges is very annoying, specially on high ISO wildlife pictures, which usually need some added cropping (robins are really small!!!).

The beauty of the Equalizer tool is that for colour and luminance noise reduction, you can taylor the size of details within your image that it applies too, and the level of effect on each-sized detail. As I mentioned previously, it takes a little experimentation and practice, but it's worth it. Start with the "denoise chroma" preset in Equalizer, and adjust it to suit, adjusting the "mix" up or down to increase or decrease the level of effect.

Excalibor · 08-12-2018, 12:49 PM

Originally posted by BigMackCam

The demosaic tool is in the "basic group", here:

(snip) (snip)

Thanks a bunch for the info! I will play around and come back with my findings...

Cheers!

08-04-2018, 12:04 AM	#1
Tranzistors Senior Member Join Date: May 2009 Location: Latvia Photos: Albums Posts: 112	Denoise in Darktable is not as good as I hoped It is a well known truth that RAW files have less noise than JPEGs, except for me don't. When shooting at iso 6400 my K-1 does a pretty good job of reducing color noise and there is some fuzziness around edges. When I open the RAW version in Darktable, it has some serious light show going on. All the denoising strategies I could find were either too aggressive or even gave details that were just not there. To give a better idea of what I mean, I made an experiment. The first two images are at ISO 100 to give a baseline. The denoise was up to the maximal available level or until the light noise was gone (the module used is in the description of the images). None of the results came anywhere near what the camera could do so either I am really really bad at this or Darktable is really bad at this. I might consider moving to RawTherapee. Lightroom is not even considered since I'd rather upgrade to K-1ii, which is has much more manageable color noise than my K-1, that is to say that applying default profiled denoise it gets rid of the already minimal color noise and doesn't destroy details.

08-04-2018, 03:47 AM - 3 Likes	#6
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,674	I thought the same as you when I first started using Darktable, but in fact it has incredibly powerful noise reduction - to the point where I now far prefer it over Lightroom, primarily because of the range of tools and fine control it provides, along with retention of detail (if you use the tools properly). But it takes some learning to understand how everything works. The first thing you need to do is select an appropriate demosaicing algorithm for your photos. By default, Darktable applies "PPG (fast)", which allows for fast on-screen rendering, but results in a noisier appearance. My favourite is VNG with five times colour smoothing, but many prefer AMaZE. VNG produces a smoother result, AMaZE produces a perceptually-more-detailed result (but with maze artefacts that I don't personally like). With your demosaicing sorted out, there are several Darktable tools you can use to reduce both colour and luminance noise. I prefer the Equalizer tool for both (using separate instances of the tool - one blended uniformly for colour, the other for lightness), but there's a bit of a learning curve involved - it requires some trial and error and practice. If you're shooting really high ISO images, the Equalizer won't get rid of all colour noise, but gentle use of the Denoise (bilateral filter) - radius 30, 0.050 for the red, green and blue channels (blended uniformly for colour) will usually eradicate the rest of it. I don't like to use the bilateral denoise on its own for colour noise reduction - I only ever use it in tandem with the Equalizer. Finally, be sure to adjust the threshold in the Sharpening tool, as it will sharpen remaining noise if you leave it set at the default setting of 0.500. I adjust it on an image-by-image basis, but typically start with a setting of 1.200. This ensures that edges are sharpened, but minimises sharpening of noise. Last edited by BigMackCam; 08-04-2018 at 04:37 AM.

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08-04-2018, 12:53 AM	#2
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Uh... actually thr opposite is true... RAW files generally have more noise than JPEG files, since they haven't gone through the noise reduction algorithms in camera. It's up to you to do the NR and find your ideal balance between noise reduction and detail preservation, something you can't do very effectively with JPEGs because compression artifacts get in the way. Not familiar with Darktable, but you could try the Google Nik collection of plugins (you'll need a host software), which has a pretty good (and free) noise reduction module.

08-04-2018, 02:03 AM	#3
house Pentaxian Join Date: May 2015 Photos: Albums Posts: 3,306	I can't see your files due to flickr sign in required. There are many ways to denoise in Darktable and you can always tune the behaviour to your liking. This one is quite processing intensive but quite good Darktable Tricks - Processing - discuss.pixls.us Originally posted by asn at pixls.us: The denoise triple denoise (profiled) instance 0; wavelet; strength 1; opacity: 100%; blend mode: color denoise (profiled) instance 1; wavelet; strength 1; opacity: 50%; blend mode: lightness denoise (profiled) instance 2; non-local means; strength 1; opacity: 30%; blend mode: averaging I’ve created presets for those which I called (instance 0, instance 1, instance2). Follow the link above and there are other suggestions in the thread.

08-04-2018, 02:10 AM	#4
Tranzistors Senior Member Join Date: May 2009 Location: Latvia Photos: Albums Posts: 112 Original Poster	Originally posted by LensBeginner Uh... actually thr opposite is true... RAW files generally have more noise than JPEG files, since they haven't gone through the noise reduction algorithms in camera. It's up to you to do the NR and find your ideal balance between noise reduction and detail preservation, something you can't do very effectively with JPEGs because compression artifacts get in the way. Not familiar with Darktable, but you could try the Google Nik collection of plugins (you'll need a host software), which has a pretty good (and free) noise reduction module. I understand that RAWs will be nosier before I do any noise reduction. All I want is to be able to at least replicate the noise reduction that my camera is capable of.

08-04-2018, 03:39 AM	#5
parinya-ekparinya Senior Member Join Date: Nov 2017 Location: Bangkok Photos: Gallery Posts: 114	I use darktable for more than a year. Using this software is not straightforward. I would say there are so many things you could do (and should do) for noise reduction. For example, instead of using only one denoise profile, darktable usually gives you a better result if you use two denoise profiles with different blend modes: one for chroma noise and another for luma noise. You could even go further with bilateral filter and equalizer for noise reduction, but that requires time to tweak things. Nowadays, I mostly rely on DxO Optics Pro for noise reduction. :-)

08-04-2018, 04:38 AM	#7
twilhelm Loyal Site Supporter Join Date: Feb 2009 Location: Florida Photos: Gallery \| Albums Posts: 2,369	Mike did a great job explaining Darktable. I’d like to emphasize learning to use the equalizer, especially multiple instances of it. On another note, Rawtherapee is also very good, especially with AMaZE. A good starting point would be to read squirrelmafia’s thread on Rawtherapee. He spent a lot of time creating presets for high ISO photos.

08-04-2018, 04:51 AM	#8
MaineNative Senior Member Join Date: Jul 2017 Photos: Gallery Posts: 280	I have used Noiseware as a plug-in to Photoshop, but I think it can run stand-alone. It has different selections for standard noise reduction, strong noise reduction, portraits, landscapes or night shots. The choices adjust the noise removal and detail protection very well IMO.

08-04-2018, 06:50 AM	#9
Roadboat24 Pentaxian Join Date: Jul 2017 Posts: 487	I also use Darktable and as others have said, there is a learning curve. If I'm impatient I also use Noiseware Standard Edition. It's fast, easy, uncomplicated and does a pretty fair job.

08-04-2018, 10:47 AM - 1 Like	#10
Tranzistors Senior Member Join Date: May 2009 Location: Latvia Photos: Albums Posts: 112 Original Poster	Originally posted by BigMackCam Finally, be sure to adjust the threshold in the Sharpening tool THIS. I had “sharpen” auto-applied to all my images (seems like default Darktable behavior). When I removed it, suddenly all suggested denoising strategies became usable. Thank you for restoring my sanity. Originally posted by house This one is quite processing intensive but quite good Darktable Tricks - Processing - discuss.pixls.us This IS good. I guess I'll lose a couple of hours trying stuff out. Originally posted by twilhelm On another note, Rawtherapee is also very good I plan to look into it. Darktable has tethering (and I hope it will support K-1), but RawTerapee is written in C++ and gtkmm, which I prefer over C and GTK+ (if I ever get to contribute to any of those projects, that might become relevant).

08-04-2018, 11:06 AM	#11
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,674	Originally posted by Tranzistors THIS. I had “sharpen” auto-applied to all my images (seems like default Darktable behavior). When I removed it, suddenly all suggested denoising strategies became usable. Thank you for restoring my sanity. You're very welcome. In the beginning, That was one of several things that tripped me up too

08-04-2018, 02:19 PM	#12
Mikesul Loyal Site Supporter Join Date: Sep 2009 Location: Phoenix, AZ Posts: 7,594	I have not used DarkTable but this thread has been encouraging in that is demonstrated that seemingly complex problems with unfamiliar software can have easy fixes. I may give it a whirl.

08-12-2018, 09:51 AM	#13
Excalibor Senior Member Join Date: Jul 2018 Posts: 353	Sorry to wake up an old thread, but i don't think my doubt merits a new thread. Some of you mentioned that you changed the demosaicing algorithm and took the automatic sharpening away... Where in the config can I change these things? I have had quite satisfactory results sliminating noise and haze with Darktable, by using denoise and also by playing with the color channels, but the proposed solutions really look like an improvement... I don't usually mind luma noise, I might even enhance it and switch to black&white; plus my K-3 has a very nice noise, if that make sense: but chroma noise is definitely a nuisanse, and the loss of sharp edges is very annoying, specially on high ISO wildlife pictures, which usually need some added cropping (robins are really small!!!). Thanks in advance! :-)

08-12-2018, 12:09 PM	#14
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,674	Originally posted by Excalibor Some of you mentioned that you changed the demosaicing algorithm and took the automatic sharpening away... Where in the config can I change these things? The demosaic tool is in the "basic group", here: ... while the sharpen tool is in the "correction group", here: Originally posted by Excalibor I have had quite satisfactory results sliminating noise and haze with Darktable, by using denoise and also by playing with the color channels, but the proposed solutions really look like an improvement... I don't usually mind luma noise, I might even enhance it and switch to black&white; plus my K-3 has a very nice noise, if that make sense: but chroma noise is definitely a nuisanse, and the loss of sharp edges is very annoying, specially on high ISO wildlife pictures, which usually need some added cropping (robins are really small!!!). The beauty of the Equalizer tool is that for colour and luminance noise reduction, you can taylor the size of details within your image that it applies too, and the level of effect on each-sized detail. As I mentioned previously, it takes a little experimentation and practice, but it's worth it. Start with the "denoise chroma" preset in Equalizer, and adjust it to suit, adjusting the "mix" up or down to increase or decrease the level of effect.

08-12-2018, 12:49 PM	#15
Excalibor Senior Member Join Date: Jul 2018 Posts: 353	Originally posted by BigMackCam The demosaic tool is in the "basic group", here: (snip) (snip) Thanks a bunch for the info! I will play around and come back with my findings... Cheers!