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Thoughts on imPPG Lucy-Richardson vs Registax wavelets for sharpening?

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#1 FlankerOneTwo

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Posted 16 October 2017 - 05:20 PM

Hi all,

 

Somehow I just discovered imPPG and Lucy-Richardson deconvolution; apparently this is available in Astro Image as well. I'll confess I have a rather basic understanding of deconvolution as compared to wavelet sharpening, as I understand it the former being the removal of an estimated transfer function from a signal and the latter a multi-layer signal-frequency based unsharp masking. It is not intuitively clear to me if either one is generally superior to the other for solar image processing, or in what specific situations to apply one vs the other. Or one after the other.

 

I'm currently imaging with a QHY5III 174 in either a Lunt LS80THa or a Quark Chromo in an ES ED127.After a lot of experimentation, I think what I I'm looking to achieve is a smooth detailed image without harsh over-sharpening edges or excessive contrast, and trying to develop a standardized workflow to accomplish this. I know that probably what I really should have is a full aperture D-ERF, but the cost is prohibitive at the moment so I'm not looking to compare to ValeryD's images!

 

Below are two of my efforts from this morning with the LS80 using AutoStakkert, imPPG, and Photoshop. Any thoughts on L-R vs wavelet? I read the other CN threads that I found on it, left me almost more befuddled than before.

 

Thanks!

Attached Thumbnails

  • Sun_091734_lapl5_ap375 sharp2.jpg


#2 FlankerOneTwo

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Posted 16 October 2017 - 05:22 PM

Earth only approximately to scale and not to be used for celestial navigation :-)

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  • Sun_092244_lapl5_ap433 sharp2.jpg

Edited by FlankerOneTwo, 16 October 2017 - 05:23 PM.


#3 bob71741

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Posted 16 October 2017 - 05:41 PM

Pat - I'd look on solarchat for info on Lucy-Richardson deconvolution; there are several posters there using the technique, but look for Chris Schurs' posts as he is the L-R expert in my opinion (and others) as shown by his processed images.

 

He has not posted on solarchat and CN in quite a while, so do not expect an answer if you reply to any of his posts.



#4 RickV

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Posted 16 October 2017 - 08:32 PM

Hi Pat!

 

Great images!

 

I used to use Registrax wavelets for all my sharpening... but no more.

Registrax wavelets were great for planetary.

However, when I changed cameras and celestial targets, I discovered that Registrax can't handle images larger than 2048 x 2048 pixels.

 

That's when I bought Astra-Image... with all its sharpening routines, including wavelets and several deconvolution processes.

On H-Alpha solar images I rarely use wavelets anymore... just too easy to get shiny-bubble artifacts.

For H-Alpha images of the solar surface I use:

- Astra-Image: Lucy Richardson deconvolution (10 passes, Kernel 1, Strength 3) and a Cauchy distribution.

- Photoshop: Unsharp Mask

- Photoshop: High-Pass Filter

 

I recommend Astra-Image; I got both the Photoshop Plug-in and the stand-alone version.  So far, I've only used the Photoshop Plug-in... very convenient.



#5 FlankerOneTwo

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Posted 16 October 2017 - 11:31 PM

Thanks guys, I'll look into Astra Image and Chris Schur's stuff! A Photoshop plugin sounds convenient, instead of having to skip around between all these different programs.




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