1999.11.30 22:23 "libtiff 3.5.3 release.", by Michael L. Welles

1999.11.30 23:22 "Re: libtiff 3.5.3 release.", by Daniel McCoy

Thank you for this change. I always wondered how LIBTIFF could get by this long.

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 has a web page about it.


Also lists a contact email address.

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.

Exactly. And Unisys is counting on just that.

The word used to be that the patent only covered compression. That may be true, but Unisys is claiming it controls decompression as well and if you disagree with them, you better have a lawyer handy. Folks also used to assume that it was commercial use of the software that was covered, so that libtiff could be distributed freely, "for educational purposes", but you needed to talk to Unisys if you used it for commercial purposes. That may be true as well, but Unisys is claiming all distribution of software requires a license from them and you better have a lawyer if you want to argue about it.

Like many US companies, Unisys is claiming a very wide interpretation of their patent rights. The idea being that the license fee is much less than the lawyer fees to fight it, so companies with enough resources to fight it won't bother because it's cheaper not to.