[fitsbits] Description of FITS Rice compression algorithm {External}

[Barrett, Paul]

Is anyone aware of a description of the Rice compression algorithm that is
used by FITS?

The only pseudo-description that I can find is the ricecomp.c code in the
cfitsio repository. It would be nice to have a
language agnostic description. Note that it is a non-standard algorithm,
because it divides the data into subarrays and performs some preprocessing
of the subarrays before compressing the data. The standard Rice compression
algorithm does not perform preprocessing.

I should also note that cfitsio does not have an algorithm for Int64 types;
only Int8, Int16, and Int32. The FITS specification permits all four
integer types. I guess no one does Int64 compression.

 -- Paul


-- 
Paul Barrett, PhD
Department of Physics
The George Washington University
Washington, DC 20052
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listmgr.nrao.edu/pipermail/fitsbits/attachments/20250814/3ca56660/attachment.html>