rick@uunet.UU.NET (Rick Adams) (08/06/90)
Archive-name: lzw-patent/05-Aug-90 Original-posting-by: rick@uunet.UU.NET (Rick Adams) Original-subject: Re: Imagine if you couldn't use compress any more Archive-site: uunet.uu.net [192.48.96.2] Archive-directory: /pub Reposted-by: emv@math.lsa.umich.edu (Edward Vielmetti) The text for patent "4,558,302 Dec. 10, 1985 Welch" can be ftped from uunet.uu.net as pub/lzw-patent.Z It's fun (and virtually indecipherable) reading. For example, they claim 10. The compression apparatus of claim 5 further including initializing means for storing in the locations of said memory means an empty indicia signal representing that the location storing said empty indicia signal is empty, said empty indicia signal having a value not equal to any compressed code signal. or, as best as I can figure out int table[N] for(i=0;i<n;i++) table[i] = NIL; is one of their intellectual property claims. (So be careful about initializing your tables!) There are 181 claims, many as specious as this (and many probably legitimate "invention"). --rick