PsfImage Problem

krphotogs

Active member
I have run this script for some time, but recently images providing a problem. When I run the script, I get about 2000 stars in the bottom left, and it runs for a few minutes then comes back and says "No Stars Found". I moved the slider from 1, to 0 to -.7 (then about 4000 stars in bottom left) - but no different. I ran it on the color linear image as well as a luminesce channel (linear). What am I missing?

Kevin
 
Kevin,
I suspect the problem is with your image and not the PSFImage script. From my observation, it appears that the stars in your image are just enough out of focus (the dim ones), or have severe diffraction artifacts (the bright ones), that PSFImage cannot find any that have acceptable Moffat profiles. When you run PSFImage with increasing sensitivity (moving the slider toward negativity), PSFImage is just searching (and finding) a larger set of the out-of-focus stars (and possibly hot pixels) in your image.

Randy
 
Definitely a possibility Randy - but I have seen this script work on images that are worse in focus. I guess I need to investigate more of the differences between Moffat and Gaussian, as do it the manual way was only bringing up Gaussian files. Thanks for the input!
 
... the stars in your image are just enough out of focus ...
Following up on this I tried one iteration of MorphologicalTransformation erosion with a 3x3 "+" kernel and PSFImage then worked fine (of course this would usually seriously degrade any real PSF).
 
I created a PSF manually - and all I found were gaussian stars, so guess the script is working. I am puzzled over what would cause that - I did 3 images over 2 nights and 1 was fine, the other 2 no.
 
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