SFINX software tree - FITS
FITS is the
Flexible Image Transport System,
an image format understood by most astronomical packages (and some general
packages as well).
Reading and writing FITS from astronomical packages
This document can of course only show a small part of the possibilities;
one should look up the documentation of the astronomical software in stead.
Converting to and from other image formats
As part of the ImageMagic package, there are
commands to convert FITS images to general gray scale images. These are
fitstopgm and fitstogif. There are also
programs called pgmtofits and giftofits
to do the reverse conversion, but of course such FITS files lack the
specific information usually present in FITS files, such as coordinates.
Viewing FITS files
In stead of reading a FITS file in into an astronomical package, or converting
it to a gray scale image, you might sometimes want to view it directly.
For this purpose, there is a program called XFITSview
(also available as xfitsview). This program allows some basic
image manipulations and color schemes, and you can even use it to blink images
or create simple movies.
Another program (available only on the Sun computers) is
fits-bds. This is a rather primitive utility.
Other FITS utilities
The program fitshead can be used to list the header keywords
of a FITS file. The default is to list only the main header. With the
-x option, it will also list any extension headers present in
the file.
The program fitskey searches for a specified FITS keyword
in the header of a FITS file.
The program verifits verifies a FITS file according to
the official FITS specifications (only available on the Suns).
FITS tapes
Apart from the image format, FITS also specifies tape formats for exchanging
data between computers. The astronomical packages all know this standard,
so no additional work is necessary. But sometimes you need to copy files
from a FITS tape to disk, e.g. when a FITS reader doesn't support tapes.
The proper UNIX command to copy a FITS file is
dd if=$TAPE of=file1.fits bs=2880
Note: sometimes you will need bs=28800
David.Jansen@strw.leidenuniv.nl
Last modified: Wed Apr 24 09:34:16 MET DST 1996