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,
I'm working on a little 2x2 mosaic and I've noticed strange artefacts in the stars shape : scare center, dark borders...
The single stacked frames don't show any artefact, only the mosaic. See the joined picture : 300% zoom, single stacked frame on the left, mosaic on the right side).
By looking at my previous mosaics, the artefact is also there.
So I think the issue might come from the parameters used, or not 😀Â
Here are my usual settings :
3 - Â stars count at 5000
4 - quadrilaterals, scale 1 to 10, DDC and same camera and optic checked, mosaic registration mode and projective
5 - advanced mode and defaults parameters
6 - mainly defaults, full mode, LNC 1-3, MBB 15, no rejection, no drizzle
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Thanx for your feedback.
David
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300% - that is some pixel peeping 😊Â
Only thing that comes to mind immediately - you really need 5000, I usually use 3000 at best (although I don't think this has anything to do with your problem.
What is your imaging gear ?
Hi David @dav78,
It looks to me like there is downscaling in play together with Lanczos data interpolation. Are you creating the mosaic using frames with different image scales?
The artefacts migh be avoided by
- using another data interpolation filter, like Cubic B-Spline, or
- preventing the possible downscaling
- or using drizzle integration instead of non-drizzle integration, just enable drizzle, use scale 1.0, droplets of 1.0 and the tophat kernel, that should really give you better stars 😉
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Cheers,
Mabula
Hi,
@einari, yes 300% is definitely a huge pixel peeping 😉, the purpose was to show the issue. But looking at the full mosaic, it's not so bad, but some stars have a strange shape. My gear is A7S modified + TS Star 71.
@mabula-admin, thanx for your quick feedback ! The different pictures were just cropped to avoid bad sides, but they have the same scale, at least I think. I will try your solutions and be back here soon 😀Â
I tried a few things :
1 - lanczos3 as usual, with the issue
2 - Cubic-Spline : the stars are perfectly round, but much bigger, and very soft, as the background
3 - Drizzle 1 : the better result, with stars just a little bigger than the single stacked frame, but with a softer background
4 - Billinear : similar to drizzle 1, but the stars seem to be a little bigger.
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What do you think about those results Mabula ?
