[AstroPy] pyfits query: how to include a bit mask?

Russell E Owen rowen at u.washington.edu
Mon Oct 10 18:37:32 CDT 2005


At 3:09 PM -0400 2005-10-07, Christopher Hanley wrote:
>Russell,
>
>My suggestion depends upon the type of FITS file you are creating. 
>If you are dealing with FITS images, I would just add another 
>extension to your FITS file containing the data quality flag values 
>you wish to use.  If you are writing FITS tables you could just add 
>another column with the desired bit value.

Thank you for the helpful reply.

These are simple fits images (one per fits file).

If I add an extension then it will have to be at least 16 bits/pixel, 
right? The two masks I want to add are only 1 bit/pixel each (I could 
combine them into one, but they'd just have to be separated out again 
at the other end).

Is there a natural and straightforward way to store the data in the 
fits file more efficiently? Transmission time is an issue (we could 
use compressed transmission, but that has its own headaches).

-- Russell




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