Hello everybody,
Sorry I will speak in english.
I would like to add some explanation to what Steffen said.
About the comparizon of Siril and APP. I really would like to read the comparison. I bet it has been done with an old version of Siril.
Now, I can say that if PixInsight is really better (probably the best astrophotography tool), APP and Siril are playing in the same category. For example, since the 0.99.4 we have introduced a bunch of new algorithms to debayer images. These algorithms have been developped by the RawTherapee team and one of them is really good for astronomy images (and really fast too).
The algorith RDC is dedicated to round objects (like stars) while VNG gives really poor result in high contrast objects (like .... stars). APP does not use VNG, that's true (PI does), they use their own algorithm.
I did some tests. As you may know, Siril has no Bayer Drizzle algorithm yet. So, it was decided to implement it in Siril 0.99.4. But before I did some tests.
These tests are here:
I tried to stack a large set of frames (more than 100) with different parameters including those recommended by the author of APP.
What I can say is that APP and its Bayer Drizzle algorithm is really better (in terms of resolution) only in one situation: the point Kernel. This parameter is not really recommended as it adds a lot of noise in the image.
Also we use the same technic as Pixinsight for alignement with two algorithms (pattern matching and RANSAC). That makes alignment really good when star detection tool detects enough stars.
So my conclusion was that even without the Bayer Drizzle but with the RDC algorithm, Siril can give really sharp results. But it is like a lot of software, if you just click on one button, don't expect the best of your images.
In the future we want to combine all the advantage of RCD with the advantage of VNG to obtain a new algorithm that would be better (but slower).
So now, about the speed. Indeed, Siril goes fast, and we are working a lot on this feature. Every algorithm is optimized and multithreaded. Since the new beta version, FITS file used are twice as large in size as before and the memory used is also twice as large. However, where one would have expected twice as long computation times, a lot of optimization work was done throughout the code.
For comparison, on a machine with an I9 core, 32GB of DDR4 RAM (a good machine), a stack of 47 images takes 5min 24s with version 0.9.12 while only 2min01s are needed to stack 32bits images under 0.99.6.
About documentation, it is true that Siril evolves really faster than the documentation. I'm Sorry for that, but writing code is taking us so much time we don't find the energy to write documentation. Don't forget we are only 2, on our free time and this version was really tiring to code. Contrary to APP or PI, we don't make any money with Siril. Volunteers are always welcome.
I hope my message was not too long,
Cyril
youtu.be
