[sclug] OT Looking for interesting stories on copyright etc

[Bob Franklin]

On Mon, 1 Sep 2003, Bob Redknap wrote:

> Sorry if this has been covered already, I haven't been paying close
> attention. File compression sounds mathematical - wasn't there an issue
> once with GIF images and Compuserve claiming copyright ?

It's the Lempel Ziv Welch (LZW) compression/decompression algorithm,
patented by UNISYS.  It expired on 20th June this year in the US and on
the 18th June 2004 in the UK:

  http://www.unisys.com/about__unisys/lzw

There was a big drive to get people to use PNGs to avoid paying for a
licence, a few years ago, but that seems to have fizzled out.  PNGs are
used now, but still not extensively (of course, they have other benefits).

  - Bob


-- 
 Bob Franklin <r.c.franklin at reading.ac.uk>          +44 (0)118 378 6630
 Systems and Communications, IT Services, The University of Reading, UK