Problem with fits images - Pixel storage file is truncated
alexg wrote on Aug 28, 2007
To whom it may concern,
I am reducing some slit spectra and have encountered a problem I have never seen before. First of all, 3 of my CCD images(2176 x 640 pixels) seem to have been cut into 2 pieces and then re-arranged! I really have no idea how this happened. :? In any case, I tried to find a solution to this problem and eventually realised that I could do the following:
1. Use imcopy to select the two regions and output them to 2 separate files
2. Use imjoin to stitch together the 2 separate pieces
The problem is that for some reason, I cannot get acces to the final 120 columns of the CCD image (i.e. columns 2057 to 2176).
Even with a simple implot, I cannot get to those columns. I get the : "Pixel storage file is truncated" error.
Does anybody have any idea how to fix this problem???
If it helps, I have made the 3 images available here:
http://www.astro.umontreal.ca/~gianninas/iraf/
Thanks in advance!
Alex
I am reducing some slit spectra and have encountered a problem I have never seen before. First of all, 3 of my CCD images(2176 x 640 pixels) seem to have been cut into 2 pieces and then re-arranged! I really have no idea how this happened. :? In any case, I tried to find a solution to this problem and eventually realised that I could do the following:
1. Use imcopy to select the two regions and output them to 2 separate files
2. Use imjoin to stitch together the 2 separate pieces
The problem is that for some reason, I cannot get acces to the final 120 columns of the CCD image (i.e. columns 2057 to 2176).
Even with a simple implot, I cannot get to those columns. I get the : "Pixel storage file is truncated" error.
Does anybody have any idea how to fix this problem???
If it helps, I have made the 3 images available here:
http://www.astro.umontreal.ca/~gianninas/iraf/
Thanks in advance!
Alex
Mike Fitzpatrick wrote on Aug 28, 2007
The problem is that the FITS file itself is corrupt: The header extends one 80-char line past the magical 2880-byte block boundary and so what you're see is the data shifted in the display. The proper fix is to edit the header so it's the right size, e.g. delete one of the empty comments.
Cheers,
-Mike
Cheers,
-Mike
alexg wrote on Aug 28, 2007
Thank you! I see where I made my mistake now!
I wanted to add the DISPAXIS keyword and did it "by hand" by simply editing the fits file header instead of using hedit. I didn't know I could use hedit to add a keyword, I thought I could only edit what is already there! I also had no idea there was a limit to the length of the header.
Very educational! :D
Cheers,
Alex
I wanted to add the DISPAXIS keyword and did it "by hand" by simply editing the fits file header instead of using hedit. I didn't know I could use hedit to add a keyword, I thought I could only edit what is already there! I also had no idea there was a limit to the length of the header.
Very educational! :D
Cheers,
Alex
Last post on Aug 28, 2007