2026-10-09 APP 2.0.0-beta48 has been released !
This is mainly a bug fix release for the reported bugs in beta47. In addition it has a significant User Interface performance improvement noticable when you need to process 1000s of images in APP.
2026-10-03 APP 2.0.0-beta47 has been released !
This is a very big release... many code optimizations/rewrites, many parts of APP are much faster and more precise, especially star analysis and registration are much faster ! Big mosaics will go much faster 🙂
And we introduce a new preview filter, which includes the new Adaptive Deep Sky Stretch and a General Levels Stretch, this has been long over due. The old preview filter (the panel on the right side to stretch and preview your data) has not been updated for a couple of years and it is a critical part of any APP session.
Adaptive Deep Sky Stretch or ADSS is a much more intuitive stretch algorithm. It is also color preserving (which is a great new addition in itself ! ) which means that the highlights are no longer bleached, color is maintained from the linear data while stretching. You can simply stretch your data using the sky background level and signal width sliders which work much easier and more intuitive. You no longer need to fiddle with the old complicated sliders with zoom buttons. All the zoom buttons for the sliders are made redundant. And you can enter slider values in the slider value fields yourself. I will make a youtube video in the coming days to explain and fully introduce ADSS. Once the video is ready, it will be highlighted on the forum.
RGB Combine upgrade !. The RGB Combine Tool has been rewritten mostly. The tool is faster and easier to use and most importantly, the Luminance slider to inject a luminance channel or channels into the RGB composite is now working correctly. It no longer bleaches the RGB colors. Combined with the new ADSS preview, you will get much better and easier great composites with great color! I will also explain this in a new youtube video.
Hi Robert @rbarbout,
Let me first start by thanking you for pointing out this issue so clearly. I should have really fixed it now 🙂 and I think I fully understand why the artefacts occured.
The O3 channel reconstruction in 1.083 and 2.0.0-beta4 was indeed exactly the cause of the issue. Our reconstruction method was too simple.
We need to realize that the response of the O3 signal in the green and blue channels will always be different per optical setup due to :
- the actual filter used (can be any Duo/Triple/Quad NB or an O3 filter which all can have different filter characteristics)
- the actual camera's sensor QE sensitivity on these wavelengths...
- the filter characteristics of the Bayer filters (is expected to be different for diffent camera models and brands)
Because of these 3 reasons, I would never argue that it would be logical to create an O3 reconstructions using ( 2*G + B )/ 3 = O3.
It think it is more exact to try to find the actual scale factor between the response in the blue channel versus the green channel for the incoming O3 signal. This is what I implemented now and I can no longer see any checkerboard pattern like before. Noise drops clearly when compared to the 2.0.0-beta4 (beta5) version and thus SNR increases significantly. It really looks much better now!
This new fix is also relevant to the HaO3 mono result where Ha and O3 are combined to 1 signal.
Results now with the 2.0.0-beta6 version when compared to 2.0.0-beta4 (which is identical to 1.083 stable for this issue) for your data:
O3 extract results zoomed in to pixel peep, left is beta6, right is beta4:
beta6 Signal to Noise Ratio (SNR) : 3,55
beta4 Signal to Noise Ratio (SNR) : 2,66
So SNR is improved siginificantly!
HaO3 mono results zoomed in on same region, again left beta6 and right beta4:
beta6 Signal to Noise Ratio (SNR) : 4.34
beta4 Signal to Noise Ratio (SNR) : 3.02
Again, SNR is improved siginificantly!
Or in this 4 panel comparison:
On which platform (windows, linux, macOS intel or arm) do you use APP Robert? I will provide a beta6 installer with this fix so you can hopefully confirm that you see the same improvements 😉
Mabula
Hi Mabula @mabula-admin ,
Congratulation, I think you nailed it !
From the images you provided it seems you solved the problem.
I will be happy to check the fix with a "pre beta" !
I use APP on a PC running Windows 10 64bits.
Robert
Hi Robert @rbarbout,
🙂 In the meantime, we decided that we will go ahead and release 2.0.0-beta6 for all users today or tomorrow with this fix. I will send a link with the windows installer to your email adress once I have created it though so you can test quickly if you have time.
Mabula
OK @mabula-admin ,
Should be able to give it a try this evening (Paris time).
Hi Robert @rbarbout,
This is APP 2.0.0-beta6 for windows with the fix 😉 please let us know if all is okay now !
Mabula
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Perfect ! No more problem with OIII in bayer drizzle integration.
Tested with scale = 1.0 or 2.0, droplet size = 1.0 or 1.5
It's a GO for beta 6 !
Thank you Mabula and the APP team.
