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Author Topic: Pixinsight Noise Reduction  (Read 3416 times)

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Offline Roger B

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Pixinsight Noise Reduction
« on: 22:04:17, 04 November, 2014 »
My Achilles heel seems to be noise reduction in PI,   I just cannot seem to master it on most of my image, some come out well, some don't.   I have seen images from others that hardly show the back ground defects that I get, with lesser subs.

I've taken a quote from Chris B's comment regarding the use of these tools from Phillyo's image of ic1805

"Several noise reduction techniques in Pixinsight so its very much a matter of knowing what  to use and when and then to be appropriate with its application"

How do you know what one to use? Chris or anyone.    There are a few to chose from & knowing what one to try on a particular image would save the rest of my hair falling out.    :confused: :confused:

Rog
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline chris.bailey

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Re: Pixinsight Noise Reduction
« Reply #1 on: 22:19:16, 04 November, 2014 »
Roger

With good long integration data taken in good conditions TGVDeNoise can be truly spectacular applied either at a Linear or Non-Linear stage, there is a new more powerful version of TGV on its way. With slightly lesser data using the noise reduction settings by wavelet layer in Multiscale Linear Transform can work very well especially as it now has linear masking built in. The downside is that it can leave little black holes.

For day to day Noise Reduction ACDNR is still the tool of choice. the key is masking higher s/N areas and getting the settings right to avoid background clumpiness.

I now tend to do a very slight NR in the linear stage using MLT (but very gentle) followed by an application of ACDNR after stretching.

When I get a mo I'll pull out a chunk of an image and try to use all three to indicate the differences.

Chris
LX200|ZS70|FSQ85|FLT110|Altair DF250RC|EQ6 Pro(Rowan Belt Mod)|ParamountMX
ATIK383L+/EFW2/OAG|Lodestar|Baader 36mm LRGBHaSIIOIII
Starlight Express SXVRH16/ONAG/FW|Lodestar X2|Baader 2" Filters
Starlight Express SXVRH814/ONAG/FW|LodestarX2|Baader 2" Filters
Lunt LS60PTBF1200|DMK41|Quark Chromo
Samyang 135mm f1.8

Offline psjshep

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Re: Pixinsight Noise Reduction
« Reply #2 on: 23:55:35, 04 November, 2014 »
Personally... I prefer the ACDNR by far but reduce the settings by at LEAST a half..

i.e the Lightness tab, the "Amount" (which defaults to .90) I reduce to a max of 0.45(or even less), and if colour, Chrominance  is reduced from 1.00 default to at LEAST 0.5

For me, this gives enough background noise reduction without making the whole thing too soft.

This is all done as one of the final stages in the non-linear state.

Phil
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Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #3 on: 08:04:16, 05 November, 2014 »
I think that's where i get stuck,  Should i do it it linear or non linear.     

I've also read that some are for large scale noise & some for small scale noise,  Now i don't know if my noise is large scale or small scale.

Roger
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline psjshep

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Re: Pixinsight Noise Reduction
« Reply #4 on: 09:18:25, 05 November, 2014 »
I think that's where i get stuck,  Should i do it it linear or non linear.     

I have always done it as one of my last steps... therefore it is in the non-linear stage - after histogram stretching and curves-like procedure.

I've also read that some are for large scale noise & some for small scale noise,  Now i don't know if my noise is large scale or small scale.

Well... do you have a lot of noise (general background) or is it in a specific part of the object?

Phil
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Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #5 on: 09:59:43, 05 November, 2014 »
on my latest image ( That I'm about to dump ) the answer is yes to both Phil,  But normally its more background.

Roger
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline chris.bailey

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Re: Pixinsight Noise Reduction
« Reply #6 on: 11:07:51, 05 November, 2014 »
Roger

What sort of image? Mono Ha or RGB? I tend to struggle more with RGB. For mono Ha I favour TGV in the linear stage BUT you do need to use local support and you do need to turn everything right down (I am down at Strength=0.15:Edge Protection=0.000185:Smoothness=1.0:Iterations=1,000! for an image I am mid-process on). Very different settings than I would have been using for widefield images. I have never got TGV to work very well on RGB images even if the three channels are done seperately before combinining them so tend to resort to ACDNR post stretch.

Chris
LX200|ZS70|FSQ85|FLT110|Altair DF250RC|EQ6 Pro(Rowan Belt Mod)|ParamountMX
ATIK383L+/EFW2/OAG|Lodestar|Baader 36mm LRGBHaSIIOIII
Starlight Express SXVRH16/ONAG/FW|Lodestar X2|Baader 2" Filters
Starlight Express SXVRH814/ONAG/FW|LodestarX2|Baader 2" Filters
Lunt LS60PTBF1200|DMK41|Quark Chromo
Samyang 135mm f1.8

Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #7 on: 12:06:18, 05 November, 2014 »
My current image is N/B   Ha Sii & OIII but the SII & OIII were binned 2x2. ( and that's where they are gonna end up )  but basically it's all images Chris. It's easy to follow video tutorials online & follow work flows but what they do is foe their image & may not work on mine.

Rog
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline chris.bailey

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Re: Pixinsight Noise Reduction
« Reply #8 on: 12:14:16, 05 November, 2014 »
Rog

Stick the Ha up on dropbox if you want and i'll take a gander. I had a good feeling for noise reduction on the widefield setup (FSQ85/Atik383) but have struggled a lot more on the RC/H16 myself.

Chris
LX200|ZS70|FSQ85|FLT110|Altair DF250RC|EQ6 Pro(Rowan Belt Mod)|ParamountMX
ATIK383L+/EFW2/OAG|Lodestar|Baader 36mm LRGBHaSIIOIII
Starlight Express SXVRH16/ONAG/FW|Lodestar X2|Baader 2" Filters
Starlight Express SXVRH814/ONAG/FW|LodestarX2|Baader 2" Filters
Lunt LS60PTBF1200|DMK41|Quark Chromo
Samyang 135mm f1.8

Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #9 on: 12:26:08, 05 November, 2014 »
I'll bung it up later when i get home from my shift tonight.

Rog
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #10 on: 23:33:27, 05 November, 2014 »
Put the Ha in Ukai Chris,  It's straight out of PI as I left what I was doing on the mac where I was staying.

Rog
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline chris.bailey

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Re: Pixinsight Noise Reduction
« Reply #11 on: 09:21:54, 06 November, 2014 »
Roger

Nice!

My take on it is back in the same folder together with a process icon set of what I applied so you can see the settings used (I have noted which ones need an L Mask or a Star Mask). I'm sure with a bit more fiddling you can refine it further but I reckon its a fair end result.

TGV works well in my view on the linear image (see after and before). Using ACDNR post stretch with enough strength to suppress the noise introduces that crinkle glaze look around stars and brighter areas. MMT noise reductions introduce too many dark specs and overall softness. TGV avoids both.
 
If you look very closely (using undo and redo whilst zoomed in) the background blotchiness is actually faint data! This whole area is awash with it. The signal is very low but TGV does pull it out. Using a little PIP during the stretch helps differentiate between the decent data and just mush. Again a little more tweaking might be in order to do it justice.

Chris

ps what dither are you applying? View is that at least 5 pixels helps.
LX200|ZS70|FSQ85|FLT110|Altair DF250RC|EQ6 Pro(Rowan Belt Mod)|ParamountMX
ATIK383L+/EFW2/OAG|Lodestar|Baader 36mm LRGBHaSIIOIII
Starlight Express SXVRH16/ONAG/FW|Lodestar X2|Baader 2" Filters
Starlight Express SXVRH814/ONAG/FW|LodestarX2|Baader 2" Filters
Lunt LS60PTBF1200|DMK41|Quark Chromo
Samyang 135mm f1.8

Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #12 on: 14:10:26, 06 November, 2014 »
Cheers for that Chris,   I'll have play later,

As to Dithering im @ 2px do you think that's too small ?

Roger
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

Offline chris.bailey

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Re: Pixinsight Noise Reduction
« Reply #13 on: 14:33:53, 06 November, 2014 »
Roger

The advice on the PI site from the big guns suggests that dithering should be at least 5 pixels and preferably 8 or so. I am dithering at 5 at the moment. The problem with 2 is that the interpolation that happens during star alignment could put errant pixels back onto each other. I noticed a few bright spots in your image that dithering and sigma rejection should have got rid of. A bigger dither should sort that and may well give a worthwhile increase in s/n.

Chris

ps I reckon drizzling those subs may be worthwhile too!
LX200|ZS70|FSQ85|FLT110|Altair DF250RC|EQ6 Pro(Rowan Belt Mod)|ParamountMX
ATIK383L+/EFW2/OAG|Lodestar|Baader 36mm LRGBHaSIIOIII
Starlight Express SXVRH16/ONAG/FW|Lodestar X2|Baader 2" Filters
Starlight Express SXVRH814/ONAG/FW|LodestarX2|Baader 2" Filters
Lunt LS60PTBF1200|DMK41|Quark Chromo
Samyang 135mm f1.8

Offline Roger B

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Re: Pixinsight Noise Reduction
« Reply #14 on: 15:28:37, 06 November, 2014 »
I also noticed that when I started to dither.   I'll increase next time.   

I've never done drizzle.   Although have heard of it

Roger
Scopes - TS65q, W/O 110 Triplet
Mount - EQ6 PRO via  Eqmod,  Rowan belt modded
Cameras - SX694, QSI583WSG,Lodestar Guidecam, GP-Cam, QHY5II.
TS 9mm OAG
Quantum 7x1.25 EFW, Baader LRGB,Ha,OIII,SII Filters 
Quark chromo

SGPro, Pixinsight.

************AND NO TIME TO USE IT************

 

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