UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Before I release it, I will make sure that everything is working properly and then I will release it.
Hello Vincent, Wouter and Mabula. To my question. How does the quality assessment actually work in APP and what are the steps involved? Do you look at the whole picture or just part of it? I ask because I noticed that the star density is not actually comparable with image shifts (unavoidable with dithering). And wouldn't it be better to specify an area after registration in the light frames that overlaps 100% compared to the rest of the lights. Then the images in the stack can be better judged against each other.
With friendly greetings
Doesn't anyone have an opinion on this? 😟
Hi @minusman,
Quality calculations are revised after each step.
So after 3) Analyse stars, only the star count in the whole image and their median shape (size and roundness) determines the quality score since this is the only thing that we know after that step.
After registration, possible image scale differences are taken into account, so if you shot the data with different camera's, telescopes or sensor binning, APP uses the registration parameters to correct the quality scores that we had after step 3. Furthermore, yes, the registration parameters allow us to use the same area/field of view as the reference frame to correct the other frame scores using the same area as the reference frame area.
Finally after normalization, so images registered and corrected for illumination differences, noise values are also added to the final quality score of the frames.
We will publish the exact formula in the manual that is coming...
Mabula
Hi,
Could I ask a follow up question? I understand that the quality scores of the images calculated by 3) Analyse Stars are used to select the best one as the Reference Frame. Does APP use the recalculated quality scores for the frames in 4) Register or 5) Normalize for any purpose?
Thanks, Jeff
Hi Mabula, thanks for the reply. I just do not know yet which reference range is meant.
1. whole reference frame (green area)
2. or only the area where the images overlap (red rectangle)
Option 2 would have the advantage that one can judge the transparency (by clouds, light pollution, etc.) of the individual frames in relation to the reference frame better on the basis of the star number.
The images above serve only as an example.
Or am I wrong?
With kind regards
