[fitsbits] CFITSIO and FITS images...

[Nigel Eke]

This is a bit of a beginners questions, so please excuse me if this is not
the right forum...

I've recently downloaded the CFITSIO library and am using it to read FITS
files, however I've hit a bit of a problem and I'm not sure if it's down to
me (probably), the library or FITS file compatibility (possibly).

The program reads all the Fits header information okay, but seems to fail
when reading the image data.  If I look at the file the image data seems to
be divided into four (or more) parts:

The first is an initial part of the image data (16bit words); the second
seems to be the initial part of the image data again, but with each word's
two bytes swapped round,

then, and I'm guessing a bit here, repetitions of:
More image data (16bit words),
More image data (byte swapped)

When I use the fits routine to grab the image data, I get the first part of
the data fine, but then it just runs straight into the byte-swapped stuff.
The image is 290*376 TSHORT and I've tried fits_read_img, fits_read_pix and
fits_read_subset, all with the same result.

I'm hoping for some pointers to what I should be looking out for, or other
areas on the web that may have some useful "beginners guides to fits"
documents (so far I've found the "FITS standard" and the "CFITSIO library"
documentation).

Thanks in advance,

Nigel

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