Subject: Hcompress for DOS?

From: rlm at astro.physics.uiowa.edu (Robert Mutel)
Date: Tue, 19 Apr 1994 22:46:51 GMT

Does anyone know if Richard White's hcompress program [which compresses 
FITS images among others] has been ported to DOS? 

Robert Mutel
Department of Physics and Astronomy
University of Iowa
Iowa City IA 52242

Telephone: 319-335-1950      FAX: 319-335-1753
Email: rlm at astro.physics.uiowa.edu  (internet) 
       iowa::rlm (span)

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From: rlw at stsci.edu (Rick White,P443,71-4933,)
Date: Wed, 20 Apr 1994 21:29:30 GMT

>From article <CoJ3A3.F7B at space.physics.uiowa.edu>, by rlm at astro.physics.uiowa.edu (Robert Mutel):

I don't know of anyone who has done this yet, though I have heard from
a couple of people who are working on it.  One is Pete Sauerbrei at the
University of Iowa (pjs at astro.physics.uiowa.edu), but maybe you're
asking because he is having problems!  The other is Denis Priou
(priou at mesioa.obspm.fr), who is working on porting the decompression
software for the Digitized Sky Survey to DOS.

There seem to be serious problems with memory management under DOS.
I've never done any DOS programming, but if it is not possible to
effectively read the whole image into memory then the program would
have to be modified to compress the image in blocks (with resulting
changes in the output file formats.)

We have effectively done this for the compression of the STScI
Digitized Sky Survey (scanned version of the POSS & ESO plates).  There
the images are 14000x14000; we compress them in blocks of 500x500.  I
have not written code for the general problem of compressing huge
images in blocks, though.

If anyone has already done the port to DOS (or has tried and failed), I
would be interested in hearing about it too.

Rick White
STScI
3700 San Martin Dr
Baltimore, MD 21218
rlw at stsci.edu