Sirlil has the option to select sorting by FWHM, weighted FWHM, roundness, quality. I also request the option to sort by number of stars and background brightness. Atmospheric conditions fluctuate during the night and it would be nice to be able to filter out bad images. (I shoot short exposures and it’s hard to do this manually with thousands of shots)
Hi,
Weighted FWHM is already doing almost what you are asking for. It is the mean measured FWHM weighted by the number of stars matched to the reference image. For background brightness, you can run a psf on a star from your registered sequence and then look at background value from the photometry results (see demo towards the end of the video there: Siril - Siril 1.0.0-rc2). This measure already correlates quite well with wFWHM so it could be that you don’t need to remove that many after you have removed the bad wFWHM values.
Cheers,
C.