darktable ep 059 - Denoise (Profiled) in dt 3.0
ฝัง
- เผยแพร่เมื่อ 28 ก.ย. 2024
- #darktable #tutorial #denoise
In this episode, we look at the revised Denoise (Profiled) module in darktable 3.0
--------------------------------
links:
www.dpreview.c...
www.dpreview.c...
--------------------------------
As always, thanks to my tier 1 Patreon supporters:
Peter Barker
Leona Devon
Michael Braem
Jon Hoskins
Namita Bhargava
Alun Spencer
Stephen Diehl
Rohn Shearer
Nils Normann
Harald Gaidt
If you'd like to support my work, get access to these videos before everyone else, AND get access to additional content, please head over to patreon.com/understandingdarktable and pick a tier that is comfortable for you.
Thanks for the video!
I'll try to answer some of the questions ;-)
As for the difference between strength and adjust autoset parameter in non local means auto: basically strength allows you to tell dt to make the image smoother and smoother, while adjust autoset parameter allows you to tell dt that the noise you have has the characteristics of a stronger noise. So, when increasing strength does not work to smooth-out noise, you have to increase the other slider as well. Basically, you should increase it whenever you have an underexposed area that you brighten a lot during the processing. I usually stay with a strength of 0.75 for non local means and use only the slider to adjust autoset parameters and the details slider to denoise my images.
On your image, see the preserve shadows parameter is very close to 1: that's actually a case where the results we will get will be quite close to the ones we had in previous versions of dt. You may experience a bigger difference on noisier images.
Wavelets are not very good in RGB mode because they denoise each channel (almost) independently of the others, contrary to non local means that denoise all channels at once. That's why it is usually required to use a representation that splits luminance and chrominance for wavelets. The presets of dt 2.6 were using blending modes for that. In dt 3.0.1, the Y0U0V0 mode was introduced to answer this need using a transformation thought for denoising (Y0U0V0 is inspired by YUV, but especially made for denoising purpose: it tries to minimize the noise in the Y0 component and minimize signal in the U0 and V0 components, which are not exactly corresponding to R and B channels). The transform to Y0U0V0 and back to RGB are linear, so they can be used with the recent rgb workflow. In this mode, the most efficient is to increase the strength as much as needed, and then to use the curves to decrease noise reduction on some frequencies (increasing the graph values in this mode indeed does not change much the result, but reducing it does change more what we get).
Hope it makes things clearer :-)
Wow, thanks Rawfiner! Think I'm going to read that about 17 times for it to sink in! 😃
@@audio2u You're welcome! Don't hesitate if you have other questions!
Thank you, i like quite denoise wavelets with strength 0,1 on low iso and 0,4 on high iso as easy setting on test photo
It's a powerful module!
Bruce try wavelets again but you had the shadows protected heavily...ie .98 and your image is dark so likely the effect was blunted......can't say as I don't have your image but worth a check......
Good point!
Weird behavior. Not sure if that wavelet scale behavior is actually intended. Gonna give it a try these days on some of my photos made with my A7III
Dear Bruce. One thing I wanted to share is that in my calibrated monitor colors, contrast, brightness look slightly different between darktable and Photoshop while viewing the same file. Darktable shows the image little more boosted with more contrast, and saturation while Photoshop shows just a tad less so. Now which one to rely more. Which software between the two is more color calibrated???? The difference is very small but noticeable to my eye. Now over the long journey of development of Photoshop, I presume it should respond correctly to color calibration better. But not sure. For now I'm giving the finishing touch to the values in Photoshop after doing most of the edit in darktable. Please share your thoughts. Will be very helpful.
Interesting! Sadly, I don't have a calibrated monitor, so I'm not going to be able to contribute much to the discussion! The monitor I use is a Dell, and although it might not be calibrated, I feel like it is really accurate, in so far as images I process on that monitor seem to translate well to a range of other devices.
Thank U sir Ji , All Tutorial help me lot to learn darktable i deleted lightroom
Cheers!
Darktable is really kool. However, can you try Raw Therapee and compare the results to Darktable? With this same image if possible. I really like how Raw Therapee can remove noise. Much thanks
Nah, sorry. I'm really happy with darktable. I tried Raw Therapee back in 2016 when I was just getting started in linux. Don't ask me to remember NOW what I didn't like about it, but I tried darktable AFTER RT and decided that this would be my new home for photo development, processing and library management.
@@audio2u No worries. I understand. I recently started using these two programs. I found that Raw Therapee has a more simplified user interface, but excels at noise reduction. Darktable has more modules, and can tweak an image more due to that. I just wanted your take on it. Thanks anyways though.
Ep 59 wow! This one is going to take some hands on time to grasp. Thankfully this module isn't used too much but will be handy when the need arises. As always thank you!
No worries! 😃
Thank you Bruce, I've just updated to 3.0 so working my way around the system again, hope you are keeping safe and well
Thanks, you too!
Thaks, another very informative video!
When i just enable this module with default settings, it says 'found match for ISO nnn' and the result takes away a lot of details and sharpness. when i open the dropdown, i can see that it actually recognised my camera (Nikon D5200), and i can choose any ISO value, but specific for this camera. If i pick te right ISO, the noise reduction works much better (although, still, most of the time , i feel i need to increase central pixel wight to preserve all details sharp). Is there a way to make it pick not only the ISO value but also the profile for my camera automatically?
Absolutely. Watch my video on Styles. Here, you can tell darktable ïf an image matches x value for 'camera model' and x value for 'iso', then apply THIS setting. Like I said, watch that video to learn how to set it all up.
I had noticed the lack of changes too when I was using the wavelets denoise. Thought I was not doing something correctly, but looks like same for you. But thanks, I did learn more about the module itself.
Yeah, I'm still scratching my head over that, as I recall wavelets being much more effective under dt 2.6. Don't know if the underlying code has changed in some fundamental way, or what.
Thanks for this video, you help me to move easyly from DT 2.x to DT 3.0.X
Excellent! 😃
5:42 but what does "fix various bugs in algorithm" means anyway?
Your guess is as good as mine! 😃
Thanks Bruce helpful again BW
Cheers!