Presentation on “Noise reduction in astrophotography: PixInsight tools”

[Jordi Gallego]

Hi all,
I have had a very low participation on the forum in the last months as I am on a very busy professional situation at the moment and unfortunately I have not much time for astrophoto
Anyway I promised some time ago to make a presentation on noise reduction in astrophotography using PixInsight, and I did it finally last weekend.
If you would like to have it a look, you can download the powerpoint file from my webpage:

http://www.astrosurf.com/jordigallego/articles.html

There are Spanish and English versions. I already ask your indulgence for the quality if the English translation (It is quite a bit heavy file, 17 Mb, as it contains some images with a reasonable resolution).
Unfortunately this time I did not have records of my speech so you may found that some slides seem incomplete or difficult to understand without the verbal explanation.
Best regards
Jordi

[bitli]

Thank you, very instructive and useful.

When you mention the method to make mask with ACDNR, you also state that ACDNR allows smoothing the mask (sldie 48).

Should the mask not be smoothed (that is denoised) systematically ? I see often that a simple intensity stretch of the L image is used as mask for the first denoising. Does the noise of the mask not get applied to the image via the masking effect ?  My understanding is that the mask provide a mixing factor between the original and the denoised image, and if this factor is itself noisy, this is somewhat reflected in the result.

I think I had slightly bettter results with a smoothed mask when working on quite noisy images. But I do not know if this effect would be important or event significant on less noisy raws.
What do you recommend?

 -- bitli

[cs_pixinsight]

Very well done presentation.  This brought up a few new uses for tools that I have not thought about.  The workflow presented will also help me in using the tools at the appropriate times.

Thank you for your time in producing this and most of all sharing it with the community.

Craig

BTW, any chance you will be translating your other papers to English?

[Josh Lake]

Yes, this was excellent, thank you! Very good guidelines and logic, clear examples. I only wish my data was that good... 

Also, how did I never know about the RangeSelection tool?! I've been using Histrogram Transformations on luminance extractions for far too long.

[Jordi Gallego]

Thanks for the comments

I think I had slightly bettter results with a smoothed mask when working on quite noisy images. But I do not know if this effect would be important or event significant on less noisy raws.
What do you recommend?

I usually smooth a bit the masks and I think I get better results this way

BTW, any chance you will be translating your other papers to English?

The Integration images presentation is already in english. Previous papers are a bit older and I think not so interesting today. Anyway I have not much time on these days , sorry.

Also, how did I never know about the RangeSelection tool?! I've been using Histrogram Transformations on luminance extractions for far too long.

Yes PixInsight has "hidden gems" 

Best regards
Jordi

[Raymond]

Thanks Jordi for this excellent presentation and making it available.
Noise reduction is often an important part in processing my images. So your presentation is more than welcome! 

[Lex]

Jordi,

thanks for the nice work, really helps with the noise reduction task, that actually is one of the toughest for me if not the toughest 

This helps out