AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2005.09.23 21:11 "[Tiff] Additional Lossless Compression Schemes", by Frank Warmerdam
[...]
2005.09.27 02:25 "Re: [Tiff] Additional Lossless Compression Schemes", by Leonard Rosenthol
2005.09.27 03:20 "Re: [Tiff] Additional Lossless Compression Schemes", by Ron
[...]

2005.09.27 03:20 "Re: [Tiff] Additional Lossless Compression Schemes", by Ron

On Mon, Sep 26, 2005 at 10:25:32PM -0400, Leonard Rosenthol wrote:

RFC1951 - zip
RFC1952 - gzip

They use the same compression, but are mostly incompatible in other ways.

Actually gzip is a basically a single file Zip archive with a variant header.

Yes, they share a subset, but in practice that seems rarely helpful.

A tar.gz is more like a .zip (but also not the same).

Not even close!

ince in zip each file is compressed individually, while in tar, everything is first "glomed" together and THEN compressed with gz/bzip.

I meant in the sense that they add the facility to store multiple discrete 'files' -- which doesn't really seem like something libtiff would need.

(pk)Zip is an archive maintenance utility, gzip is a "unix-like" tool that just takes care of compression. It leaves it up to you to determine its format and interpretation. ie. it provides the mechanism, not the policy for using it.

When comparing .zip with .tar.gz it is quite clear which is always the winner, where speed and size are the judging criteria. One reason for that you give just above. Sorry if I over-simplified, or made an overly general and misleading comparison. More detail on that seemed to be veering off topic from the original query.

Ron