[fitsbits] Need help on changing colour scale using Linux

[William Pence]

Brian Halloran wrote:
> 
> I'm attempting to change the colour scale on an astronomical FITS image
> from a linear scale to a log scale while trying to keep the astrometry
> intact. I've tried using DS9 (this is a Linux box), but when I save it
> and try opening up the new image, it reverts to the original image. Any
> tips would be most gladly received!!

FITS is not primarily an image display format, so unlike .jpg or .gif
formats, FITS images generally contain no display scaling information.  With
programs like DS9, the user can interactively examine the FITS image with a
variety of image scaling options, but this scaling preference is not saved
in the FITS file itself.  Instead of converting the FITS image to log scale
you could instead change the preferences in the image display program to use
a log display scale by default.

-Bill Pence
-- 
____________________________________________________________________
Dr. William Pence                          pence at tetra.gsfc.nasa.gov
NASA/GSFC Code 662         HEASARC         +1-301-286-4599 (voice)     
Greenbelt MD 20771                         +1-301-286-1684 (fax)