2008.02.06 10:01 "[Tiff] Why is TIFF/zip not a default option?", by Anders Sewerin Johansen

2008.02.06 11:05 "RE: [Tiff] Why is TIFF/zip not a default option?", by Anders Sewerin Johansen


Well, the reason for my question is that as far as I have so far been able to determine the deflate option was not enabled by default, which I took to mean that the majority of the libtiff equiped systems in use weould as default not be able to handle tiff/deflate. If it turns out I was mistaken, well that's just great!

The reason for the question is that several parameters are relevant for picking a format for our purposes. Some are obvious to outsiders (size of final file, CPU requirements for rendering...), while others may not be (openness of format, availability of several open source renderes, patent issues). In particular the tiff/lzw format, while suitable on most counts (stable, well-known...) is discounted due to the patent issues past, present and future of the lzw compression algorithm/implementation. The tiff/zip format would not be discounted on the patent issue as far as I know, but might be discounted with regards to cross-platform usability, if the default Linux/UNIX system configuration did not allow for reading and writing it.

Can I conclude that most recent libtiff equiped systems (e.g. systems deployed or updated during the last five years) will support tiff/zip?


On Wed, Feb 06, 2008 at 11:01:59AM +0100, Anders Sewerin Johansen wrote:

Can anybody at the mailing list elaborate on why zip/deflate compression of image data is not enabled as a default in libtiff? Is it e.g. because it's still considered experimental, or is there some other reason (technical, legal, "inertia",...)?

Deflate is enabled by default if development package of zlib is installed (deflate depends on that 3rd party software separate from libtiff). That's how it is configured on POSIX system where we have automatically configuring shell script. If you are using MSVC compiler environment then you should enable zlib support manually and point where it is installed on your system, because we can't automatically configure with MSVC.

So I really can't understand your question, libtiff is being distributed with deflate option enabled by many vendors and there no reason to disable it.