[gnuastro-devel] [task #14315] Propagate all FITS header keywords into output FITS files

[Mohammad Akhlaghi]

Follow-up Comment #1, task #14315 (project gnuastro):

This is another very useful suggestion. 

I can confirm that all Gnuastro programs that output FITS files are like this.
They do not include any of the input keywords. 

The main reason is that the most important header keywords (mandated by FITS)
change, for example in both ImageCrop and ImageWarp the size and WCS
information change. Searching through the keywords to see which ones have
changed and which ones haven't can be a great burden in terms of
efficiency/speed.

Another issue is that in some surveys the main information is in the first
extension and the second (and etc) extentions just have the data with the bare
minimun keywords (for example one extension with the image, the next for
masked pixels, and the third for exposure/weight. 

So I do support the idea that we add a common option (for all Gnuastro
programs). When this option is given the programs can check for differing
keywords and include all keywords from the input that have not changed. 

Alternatively, a more general way would be to add a feature to the Header
program to add all keywords that don't exist in the input file+extension, from
another file+extension. I think this second option would be more general than
doing it internally in each program. 

Please share your thoughts/suggestions. This is an inportant issue and we want
to find the most elegant/robust solution to it.

    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/task/?14315>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/