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Mar 28 2026 APP 2.0.0-beta40 will be released in 7 days.

It did take a long time to have the work finished on this and it  will have a major performance boost of 30-50% over 2.0.0-beta39 from calibration to integration. We extensively optimized many critical parts of APP. All has been tested to guarantee correct optimizations. Drizzle and image resampling is much faster for instance, those modules have been completely rewritten. Much less memory usage. LNC 2.0 will be released which works much better and faster than LNC in it's current state. And more, all will be added to the release notes in the coming weeks...

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Once 2.0.0 is released, the price for APP will increase. Owner's license holders will not need to pay an upgrade fee to use 2.0.0, neither do Renter's license holders.

 

Strange "integrate all" artefacts

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(@schurig)
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Joined: 9 years ago
Posts: 71
Topic starter  

Hi,

Yesterday I processed old M 42 data with the new multi channel & integrate all functions and got some strange artefacts and combine results. See the attached pic.

I loaded all lights (approx. 30 x 15sec p. channel) with the multi channel option enabled. I used a bias, dark and a flat (all three valid for all channels). Then processed and finally stacked the images with the "integrate per channel & all option", weights "quality" and "LN MAD winsor clip", k=3, i=1. All other config default. After that I used the combine tool to merge the 4 result stacks into a final color image.

On the RGB-combined and the integrate-all stack there some strange rectangled shapes I cannot explain. Also, one star became totally red. So, what happend here?

Cheers, Stephan

M42 Artefacts


   
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(@schurig)
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Joined: 9 years ago
Posts: 71
Topic starter  

Hi,

Has anybody an idea what happend here?

Here is the orginal data: http://www.mmds.de/temp/M42_Schurig.zip

Feel free to download and process!

Stephan



   
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(@mabula-admin)
Universe Admin
Joined: 9 years ago
Posts: 5056
 

Hi stephan @schurig,

I will have a look at the data later today, but here's my initial reaction based on the iamge that you provided:

  • I can see the rectangles, this must be a problem in the LN rejection algorithm which I need to fix. The rejection map will show these rectangles as well. If you use a non-LN rejection filter, all should be okay, so you can try that at least for now.
  • the red stat seems to be the result of the red star being huge in the Red channel, compared to tiny in the blue channel. Are you using the RGB all integration as luminance in the combined result?

Kind regards,

Mabula



   
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(@schurig)
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Joined: 9 years ago
Posts: 71
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Hi Mabula,

I just re-processed and integrated the data with the normal winsor clip outlier rejection filter and the result is very good (see posting: https://www.astropixelprocessor.com/community/gallery/orion-nebula-3/ ). So the red star as well as the rectangles come from the LN rejection filter.

Stephan



   
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(@mabula-admin)
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Joined: 9 years ago
Posts: 5056
 
Posted by: schurig

Hi Mabula,

I just re-processed and integrated the data with the normal winsor clip outlier rejection filter and the result is very good (see posting: https://www.astropixelprocessor.com/community/gallery/orion-nebula-3/ ). So the red star as well as the rectangles come from the LN rejection filter.

Stephan

Thanks a lot Stephan @schurig,

That is very informative, I will have a good look at the LN filters before the next release...

Awesome Orion Nebula !

Mabula



   
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(@mabula-admin)
Universe Admin
Joined: 9 years ago
Posts: 5056
 

Hi Stephan @schurig,

Thank you very much for reporting this issue.

I have located the rootcause of the problem with the LN rejection filters 😉 and have fixed this now. The LN algorithm had a incomplete formulation actually which caused it to work NOT as expected.

All details are in the release notes for APP 1.062:

  • IMPROVED/FIXED, Local Normalization Outlier Rejection filters, the LN rejection filters had a bug. In some cases the LN algorithm was rejecting data based on wrong local intensity levels in the data, causing data to be rejected in frames that didn't needed to be rejected. Please look at the following images, this is an extreme case, an integration of 100 H-alpha frames from 5 different photographers with different telescopes and camera's (courtesy of Dutch Astroforum.nl). Furthermore, in addition to the fix, the implementation has been more optimized to reduce memory usage and increase speed.
    • Integration without outlier rejection enabled and without LNC + MBB:
APP 1062 noRejection noLNC noMBB
    • Integration without outlier rejection enabled and with LNC 4th degree + MBB 30%:
APP 1062 noRejection LNC4th MBB30
    • Integration with sigma clip outlier rejection enabled (2 x 3.0 kappa) and with LNC 4th degree + MBB 30%, with rejection map:
APP 1062 sigmaRejection LNC4th noMBB30
APP 1062 sigmaRejection LNC4th noMBB30 rejectionMap
    • Showing BUG : integration in APP 1.061 with LN sigma clip outlier rejection enabled (2 x 3.0 kappa) and with LNC 4th degree + MBB 30%, with rejection map. Notice that the rejection map shows excessive rejection on some borders, even removing part of the data completely.:
APP 1061 LNRejection error
APP 1061 LNRejection error rejectionMap
    • Showing FIX : integration in APP 1.062 with LN sigma clip outlier rejection enabled (2 x 3.0 kappa) and with LNC 4th degree + MBB 30%, with rejection map:
APP 1062 LNRejection fixed
APP 1062 LNRejection fixed rejectionMap
    • Compare the Rejection Maps between sigma clipping(left)  and LN sigma clipping(right) after FIX. Notice how LN sigma clipping is less influenced by the structures in the data, giving more uniform and reliable outlier rejection:
APP 1062 sigmaRejection LNC4th noMBB30 rejectionMap
APP 1062 LNRejection fixed rejectionMap


   
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