imalign - coordinates not found in reference file.
mangoluverin wrote on Nov 15, 2008
So i was trying to use imalign to align images, and i used imexam a to find the coordinates of 5 stars in my reference image. i put the coordinates in a text file, and when i tried to run imalign, I got an error message saying that reference coordinates were not found. Any ideas on what I could be doing wrong? Thanks!
Mike Fitzpatrick wrote on Nov 15, 2008
Could you post the parameters you used as well as perhaps the reference coords file? The output of the IMEXAM 'a' keystroke cannot be used directly so I'm assuming you created the file with just the (x,y) coords and not the entire line. Also important is the 'shifts' parameter that provides an initial offset for the target image, these offset are used to find the same stars within the specified 'boxsize'.
You might also look at other registration tasks such as WREGISTER and XREGISTER as a way to align the images.
-Mike
You might also look at other registration tasks such as WREGISTER and XREGISTER as a way to align the images.
-Mike
jaclyndp wrote on Nov 15, 2008
I am having this same problem. I have an appropriate image list file, image coords list file, and an approximate shift file. The format of both my coords and shift files are the same: x-imagecoord/x-shift TAB y-imagecoord/y-shift. Now, I am supposed to be using image and not WCS coords right? Also, my shifts should just be the difference in xref & ximage coords correct? Does my reference image have to be the first on the image list (and the first on the shift list)?
I've played around with box size, but nothing seems to work...any thoughts?
Thanks
I've played around with box size, but nothing seems to work...any thoughts?
Thanks
jaclyndp wrote on Nov 15, 2008
Okay,
I figured out why my coordinates were not found. In imalign parameters, the coords field asks for a file and not a list of coordinates. The name of my coords file was PEG1coords, and so in that field I was incorrectly entering "@PEG1coords" (doing a similar thing as the image field where it asks for a list or list file in which case you DO need the @ in front of the file name). Once I took the @ away, it worked fine.
Hope that helps!
I figured out why my coordinates were not found. In imalign parameters, the coords field asks for a file and not a list of coordinates. The name of my coords file was PEG1coords, and so in that field I was incorrectly entering "@PEG1coords" (doing a similar thing as the image field where it asks for a list or list file in which case you DO need the @ in front of the file name). Once I took the @ away, it worked fine.
Hope that helps!
Last post on Nov 15, 2008