[fitsbits] Rice compression from the command line

[Arnold Rots]

I did a simple test using bzip2 for event files on Solaris.
Sure, I got 15% savings over gzip and I'm not worried about the
compression taking about twice as long.  But the decompression taking
an order of magnitude longer than gunzip bothers me.  Even if it is
more than compensated for by what's gained in transmission time, the
users' perception will be that things are worse, since decompression
taking 10 times as long appears far worse than what a 10% reduction in
transmission has gained - even if in absolute terms there is a net
gain.
Granted, this is only true, of course, for situations where
transmission and decompression are separate actions.

  - Arnold

Mark Calabretta wrote:
> 
> On Tue 2006/07/18 16:42:28 MST, Rob Seaman wrote
> in a message to: fitsbits at nrao.edu
> 
> >> I now mostly use bzip2 (GPL, bzip.org), it usually outperforms gzip by
> >> about 10% for binary data.
> >
> >It's quite a bit slower, however.
> 
> Of course, it does depend on the type of binary data - pure random data
> should not be compressible.  I measured the 10% figure for the FLC
> animations distributed from my web site.  If the files are intended
> for download, especially very large files, the extra time taken to
> compress/uncompress them is more than compensated by the faster
> download time.
> 
> Mark Calabretta
> ATNF
> 
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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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