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Diffstat (limited to 'doc/COPYRIGHT.PATENT')
-rw-r--r-- | doc/COPYRIGHT.PATENT | 62 |
1 files changed, 31 insertions, 31 deletions
diff --git a/doc/COPYRIGHT.PATENT b/doc/COPYRIGHT.PATENT index fe3c242a..141e43ac 100644 --- a/doc/COPYRIGHT.PATENT +++ b/doc/COPYRIGHT.PATENT @@ -62,37 +62,12 @@ applied to things you implement in computer programs. This is one of the Free Software Foundation's causes. See <http://www.gnu.org/philosophy.html#laws>. +The Jbigtopnm and Pnmtojbig programs use arithmetic coding patents and +other patents covering various aspects of the "front end." -Unisys owns patents on LZW compression, which is used by Ppmtogif, and -maybe on LZW decompression, which is used by Giftopnm. IBM also owns -a patent that may cover the GIF tools. Unisys offers a license of the -patent for trivial use for $5000. Its U.S. patent (Number 4,558,302) -EXPIRED June 20, 2003. In most of Europe, the patent expires June 18, -2004. In Japan, it's June 20, 2004 and in Canada, July 7, 2004. -IBM's U.S. patent expirs August 11, 2006. - -Neither company has ever enforced the patent against trivial users of -it. <http://news.cnet.com/news/0-1005-200-1713278.html> is an article -dated April 18, 2000 on the issue. -http://www.unisys.com/about__unisys/lzw/> is Unisys' view of the -matter. For information from another perspective, see -<http://burnallgifs.org>. - -The following Netpbm components may be restricted by these patents: -Ppmtogif, Giftopnm. - -A good substitute for GIF if the patents are a problem is PNG (see -pngtopnm, pnmtopng), which was developed with a primary purpose of not -using any patented technology. - -You can also use the -nolzw option on ppmtogif to avoid using the LZW -patent. The images so generated are larger than traditional -LZW-compressed GIFs, but any GIF decoder can decode them just the -same. - -I repeat: The Unisys U.S. patent has expired. It is not an issue -for any future use of Netpbm. +JPEG patents +------------ The Pnmtojpeg and possibly Jpegtopnm programs in some cases may use the arithmetic coding patents owned by IBM, AT&T, and Mitsubishi. @@ -119,7 +94,32 @@ bilevel (black and white) images. http://burnalljpegs.org contains information on this issue. -The Jbigtopnm and Pnmtojbig programs use arithmetic coding patents and -other patents covering various aspects of the "front end." +Expired LZW patents +------------------- +Unisys owns patents on LZW compression, which is used by +Ppmtogif, and maybe on LZW decompression, which is used by Giftopnm. IBM also +owns a patent that may cover the GIF tools. Unisys offers a license of the +patent for trivial use for $5000. Its U.S. patent (Number 4,558,302) expired +June 20, 2003. In most of Europe, the patent expired June 18, 2004. In +Japan, it was June 20, 2004 and in Canada, July 7, 2004. IBM's U.S. patent +expired August 11, 2006. +Neither company has ever enforced the patent against trivial users of +it. <http://news.cnet.com/news/0-1005-200-1713278.html> is an article +dated April 18, 2000 on the issue. +http://www.unisys.com/about__unisys/lzw/> is Unisys' view of the +matter. For information from another perspective, see +<http://burnallgifs.org>. + +The following Netpbm components may be restricted by these patents: +Ppmtogif, Giftopnm. + +A good substitute for GIF if the patents are a problem is PNG (see +pngtopnm, pnmtopng), which was developed with a primary purpose of not +using any patented technology. + +You can also use the -nolzw option on ppmtogif to avoid using the LZW +patent. The images so generated are larger than traditional +LZW-compressed GIFs, but any GIF decoder can decode them just the +same. |