Message-ID: 22488.944003264@sss.pgh.pa.us
To: izumi@pinoko.berkeley.edu
Subject: Re: libtiff 3.5.3 release.
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 30 Nov 1999 18:07:44 -0500
cc: tiff@olympiakos.com
In-reply-to: Your message of Tue, 30 Nov 99 14:53:48 -0800 <199911302253.OAA07994@moica.berkeley.edu>
Sender: owner-tiff@olympiakos.com


Izumi Ohzawa <izumi@pinoko.berkeley.edu> writes:
> Now, I need a solid reference that LZW decompression is not
> covered by the LZW patent.  Nothing I have read, except for opinions
> or second-hand quotes at various forums, clearly indicates
> that decompression is not part of the patent.

> Especially, does anyone have written views from the Unisys itself
> on this?

Unisys' view is perfectly clear: they claim that decompression-only
software *is* covered by the patent.  (They have a webpage giving their
version of reality at www.unisys.com, check there for an exact quote.)

There are a number of qualified people who think that Unisys'
interpretation wouldn't hold up in court, and that a court would say
that decompression-only software isn't covered.  But AFAIK there's
been no test case to find out.  Do you want to be the test case?

> Regardless of what court may or may not rule in the end, that
> doesn't matter.  Most of us here, I think, just don't want to
> hear from Unisys counsels, ever.

Yup.  That's why I'm not shipping either LZW compression or
decompression code in libjpeg these days.  It was a relatively painless
decision for me, because GIF-reading was never a critical part of
libjpeg, but I can see that dropping the LZW decompressor would be
crippling for libtiff :-(.  Don't have any good advice...

                        regards, tom lane
                        organizer, Independent JPEG Group

