[fitsbits] Fits recognition

[LC's NoSpam Newsreading account]

On Thu, 16 Aug 2007, eggpap wrote:

> how to know programmatically if a fit/fits extension file is a true 
> fit file?

Do not understand exactly your question :

 - if you mean if a FITS extension (extension HDU, other than
   primary HDU) can be considered as or extracted into a standalone FITS 
   file, this is generally not true, some form of minimal primary 
   header, with no primary array, will be required anyhow

 - if you mean that the extraction of the extension HDU with minimal
   header massaging instead of adding a minimal primary header, this
   is true for IMAGE (or IUEIMAGE) extensions. They can be very easily 
   turned in standalone FITS files (replacing the XTENSION keyword with 
   a SIMPLE keyword)

   any other kind of extension REQUIRES the presence of a primary HDU
   with no data array 

 - if you mean just testing that a generic FITS file is well formatted,
   you'd need to run a verifier program like fverify


-- 
----------------------------------------------------------------------
nospam at mi.iasf.cnr.it is a newsreading account used by more persons to
avoid unwanted spam. Any mail returning to this address will be rejected.
Users can disclose their e-mail address in the article if they wish so.