TGVDenoise 1.0 Released

Juan, Carlos

Thanks very much for the time and effort, just when I thought I was getting use to ACDNR :D

Julian
 
Another super tool from the PI team.

It has all the sliders needed to reduce the dreaded noise and I find the default settings are a good starting point.

What other software offers improvements and support we continually enjoy with PI ? And at no extra cost !!

Thanks to all.....

Regards, Colin
 
Guys:  I always appreciate your hard work at improving your software.  The sophistication and capability of PixInsight is simply remarkable.  You can made a blink person see the light (figuratively speaking of course).  Many years ago I would never have imagined that I could produce the astro images that were only attainable at world class observatories.

A truly loyal user of PI.
 
Strange, I saw how PI downloaded the update, but after restart I can't find it anywhere.
Any ideas what went wrong? I'm on 1.8 RC7 Win 7 x64.
 
Hi guys, Thanks from me too for all your hard work in the past. I noticed the term 'diffusion' in Juan's post. This isn't the 'anisotropic diffusion' replacement for ACDNR that's been hinted at in the past is it?

I'd like to see the NR tools streamlined at some point. I'm a minimilist by nature and the choices seem overwhelming already. As we all know, one can spend an hour fine tuning any one process. Give me two great ones, rather than ATWT, MMT, ACDNR, GREYC, TGVDN, Anisotropic Diffusion...
That's just me.  FWIW, I find LRGBC's CNR very powerful!

Carlos can you compare TGVDN w/ say GREYC from a practicle standpoint- talk of algorithm's will be wasted on me. ;>)

Do you see TGV as a fine-finisher or as a primary denoiser?

Lastly, I find ACDNR's specific approach for chrominance noise to be something important for NR processes. I hope its replacement addresses this.

Thank you and keep up the work!
 
Hi Warren. Yes, this is the replacement we talked about earlier. Indeed TGV may be interpreted as anisotropic diffusion, if we see the iterations as a time evolution. The main difference from TGV to other anisotropic diffusions (normal total variation, and graycstoration too, up to some degree) is that they assume that images are patches, of homogeneus pieces. In other words, images are piecewise constant. TGV, on the other hand, assumes that images are piecewise smooth. This is the advantage of TGV, and why it generates far less artifacts (like, staircaising).

I'm not an expert on the interns of GREYC, but I know that is based on TV, and tries to overcome the staircaising artifacts by using some big modifications to the main algoirithm. The "problem", is that it has been designed for daylight, normal images, with gaussian noise. In that sense, our implementation of TGV is more flexible, since it works with linear or nonlinear data, and the use of the local support frame adds the capability to deal with poisson noise.
Also, from the user point of view, I think that TGV may lead to some "lost of detail" compared to GREYC, since the piecewise constant constrain enhances more sharp edges. But at the same time, TGV will look far more natural, with smooth gradients, and will avoid some of the typical "weird pixels" that arise near sharp edges with GREYC. IMHO, TGV is on top of the wave right now, and it should be even more powerfull in future releases. We have a major upgrade under development, and have several research lines already plotted.

Now, about when to use TGV best... The truth is that we don't know yet. I think that both steps combined will prove to be a good choise. I would use it first at linear stage to smooth a bit the data (low strengths), to facilitate the first stretch and intensity adjustments. Then, I would use as a finisher, to really smooth the background and low signal features (up to taste).

ACDNR based its philosophy on SGBNR :) And yes, we kept that in TGV too. Luminance/Chrominance separation is crucial to many denoising problems. Nevertheless, if in linear stage, I should probably try working on RGB first. Just thinking as a purist. But, of course, you all will help us find the best uses and applications of this new tool. 
 
I cannot for the life of my find this tool in my release.  I am using 1.08.00.1015 (x64) RC7,  Any suggestions would be very welcome.

Thanks

Mike
 
Mike, did you saw that PI downloaded that update?
If so, go to Process/Modules/Install Modules/
on the window that will open click on "Search" , it should find TGVDenoise module.
Click on "Install" and it should work.
I don't know why it didn't that automatically as always but installing manually works.
 
Something really strange happened to me. Yesterday I replaced my previous 1.8 version by the newer 1.8 RC7 just to install the TVGdenoise module and give it a try.
Everything worked ok, after installing 1.8RC7 a popup window informed about 7 available updates (one of them the TVGdenoise module), I installed them and restarted PI. Then the TVGdenoise module was there under NoiseReduction folder. I was trying it with an old image and got some promising results.
This morning I have started PI and the TVGdenoise module was not there any more, I can't find it under NoiseReduction neither under AllProcesses. Curiously, I click on "View Installed Updates" and it's there, but there's no way to find it under the process menu.
I'm running PI 64-bit version for Windows. Any help is welcome.
 
So far I resisted on the 1.8 RCxxxx upgrades, sticking with 1.7, but finally this tool got my attention and helped me to made my mind. I installed RC7 yesterday night and tried TGV on some (very noisy) Ha and O3 frames.

Indeed, it seems to be a very strong tool BUT, where is the preview button and where is the mask generator from ACDR ?  >:D

It is a really pain already due to lack of documentation, how about a real time preview window to assist us to experiment?  And no, applying to previews is not the same.  Com'on guys, you have the code from ACDR, reuse it and make this tool the best ever !!!  ;) (I may offer to assist in adding the code for free, but I'll have to figure out a few things first, long time when I had a compiler on my laptop :angel: )
 
Update on my previous post. I uninstalled PI RC7 and installed it again from scrath including the 7 updates and the TVGmodule is there again. I have closed and started PI several times and it keeps there. However it's very strange that it disappeared the first time.

Regarding the results yielded by the tool, I don't have a clear opinion yet. I tried many combinations of parameters and tried to fine-tune them the most, but it always produced a patchy background on my DSLR linear image. ACDNR did a lot better keeping a smoother and patches free background.

Sergi
 
Increase the number of iterations. Use 300 or 500. Then play only with the noise amplitude and strength parameters (in that order).
 
cfranks said:
Wow!  The following are small sections of the original images.  There are too few subs and therefore very noisy.  My attempt at boosting the central blue saturation is crude but I was reasonably happy.  Image01 is before, Image02 is after TVG!

cfranks:

I don't know if boosting the blues boosted the noise there.  Perhaps applying the TVG before applying the blue boost would lead to a more "homogeneous" noisiness in the final image.  I do enjoy the color!
 
I find it can be a tad bit more subtle than ACDNR and I don't need to use a mask.  Is that what everyone else is finding out too?

Chris
 
Hi

I have been looking at TGVDenoise since its release and it seems I am getting somewhere with it. Have a look at the attached for the settings I have been using.

Julian
 

Attachments

  • TVGdenoise.jpg
    TVGdenoise.jpg
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  • BeforeTVGdenoise.jpg
    BeforeTVGdenoise.jpg
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  • AfterTVGdenoise.jpg
    AfterTVGdenoise.jpg
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