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.
Hello Mabula, the improved Bayer Drizzle in APP 1.072 works very well. But it's still better to have a lot of pictures because of the noise. In my experience it makes sense to use Bayer Drizzle instead of interpolation if you have more than 100 frames available. Provided the images are dithered and undersampled. My question now is, I recently had an article about Drizzle in an Astro magazine. read. It was pointed out that integration is only possible with average mode. Without outlier rejection, because the pixels of the finer grid are only alternately filled with content, which resembles the appearance of a disturbing pixel. These are sorted out with Median or Sigma Stacking. Would this also apply to Bayer Nieselregen?
This topic was modified 8 years ago 2 times by Mabula-Admin
Excellent, that is good to know ;-). Yes, it's still better to supply enough frames when you apply drizzle/bayer drizzle integration and that you dither and have undersampled data to profit from it.
Regarding your question:
My question now is, I recently had an article about Drizzle in an Astro magazine. read. It was pointed out that integration is only possible with average mode. Without outlier rejection, because the pixels of the finer grid are only alternately filled with content, which resembles the appearance of a disturbing pixel. These are sorted out with Median or Sigma Stacking. Would this also apply to Bayer Nieselregen?
First of all, drizzle and bayer drizzle are one and the same. The code in APP to perfrom drizzle or bayer drizzle is exactly the same piece of code 😉 The only difference is the input data, which in the case of bayer drizzle, is undebayered Bayer CFA data.
Indeed, if drizzle/bayer drizzle is chosen, the integration method (average or median) is forced to average. This is essential/required for drizzle/bayer drizzle integration. You can find this forcing actually in the console panel when drizzle integration starts.
Now with regard to outlier rejection, the article that you have read is rather incomplete, I would argue. It's true that due to incomplete drizzle per frame (which is perfectly normal) the pixels stacks will have zero values at those places of incomplete drizzle.
But it depends on the actual integration implementation, if this represents a problem to apply outlier rejection in integration. In APP, these zero values due to incomplete drizzle per frame, are disregarded in the pixel stack :-).
In other words, in APP, these zero pixel values are not considered in the integration, so the outlier rejection will still work properly, especially if you supply enough frames 😉
Kind regards,
Mabula
This post was modified 8 years ago by Mabula-Admin
Hello Mabula, I did a test integration once. The pictures of h and x Persei I took last year with a Canon EF f/2.8 200mm lens and the ZWO ASI294 MC Pro. There are 50 frames with an exposure time of 30 sec. pixel scale is 4.93"/pixel and all frames are sorted out without shifting. The first integration is with pixel interpolation.
The second integration is with Bayer Drizzle, droplet size 1.0 and scale 1.0. In the details you can see that the SNR is higher and the noise lower and the resolution is a bit finer.
Many thanks for the improved Bayer Drizzle, with more frames I can definitely get something out of it with my lens / camera combination. 🤗
I read the article about Drizzle again. It was on Autostakkert! 3, Registax, Fitswork and Deep Sky Stacker related. There that is probably problematic with the outlier rejection. Oh, and Dylan O'Donnell recently mentioned Astro Pixel Processor in his Star Stuff series regarding Drizzle.
Hi @minusman, can you please forward me the article and perhaps Dylan O'Donnell's mentioning of APP ?
One crucial aspect of drizzle is that integration is done with a weight map, to indicate how much % of a droplet lands on a pixel in the target pixel grid. These weights are used in APP's outlier rejection algorithms and the integration of the resulting pixel stacks.
I really think that if software has a problem with drizzle and outlier rejection, it's the actual implementation that rules the outcome, not the drizzle technique in principle 😉
It's important to realize that is you use, drizzle, especially Bayer drizzle, that the number of frames to integrate versus the ourlier rejection settings of kappa and iterations, is actually less than the real number of frames. This is due to the holes in the integration layers, due to the fact that not all pixels receive drizzle droplets.
So an integration of 100 frames, depending on the actual outlier rejection settings, can be regarded as integrating 50-75 frames with respect to the outlier rejection parameters.
Let me know if this is clear 😉
Cheers,
Mabula
This post was modified 8 years ago by Mabula-Admin
Hello Mabula, I did a test integration once. The pictures of h and x Persei I took last year with a Canon EF f/2.8 200mm lens and the ZWO ASI294 MC Pro. There are 50 frames with an exposure time of 30 sec. pixel scale is 4.93"/pixel and all frames are sorted out without shifting. The first integration is with pixel interpolation.
The second integration is with Bayer Drizzle, droplet size 1.0 and scale 1.0. In the details you can see that the SNR is higher and the noise lower and the resolution is a bit finer.
Many thanks for the improved BaExceyer Drizzle, with more frames I can definitely get something out of it with my lens / camera combination. 🤗
Excellent @minusman. that looks very good ! Thanks for sharing 🙂
