Re: Gzip uses Lempel-Ziv encoding.

Joerg Rhiemeier ([email protected])
Wed, 24 May 1995 10:34:15 +0200


Keith Ahern <[email protected]> wrote:

>I noticed that gzip uses the Lempel-Ziv coding (LZ77) scheme, Im not
>sure but is this the same coding scheme that caused that stupid GIF
>castastrophe?

No, it is not. GIF uses a different scheme called LZW. Lempel and
Ziv were also involved with the LZW algorithm, but LZW and LZ77 are,
though somehow related to each other (I don't know to which extent,
though), different. The Unisys patent only affects LZW-based
compression software, not LZ77.

>might be something to be concerned about, I dont want Unisys knocking
>on my door because my server compresses .wrl files with gzip or gzip
>code.

Don't worry. Unisys can't take gzip away.

>Is it the same compression algorithm?

As I wrote above, no.

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~/V\~| Joerg Rhiemeier, roleplayer and prog.rock maniac |~/V\~
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