TIFF and LibTiff Mail List Archive


1999.11.30 22:23 "libtiff 3.5.3 release.", by Michael L. Welles
1999.11.30 22:53 "Re: libtiff 3.5.3 release.", by Izumi Ohzawa
1999.11.30 23:07 "Re: libtiff 3.5.3 release.", by Martin Bailey

1999.11.30 22:23 "libtiff 3.5.3 release.", by Michael L. Welles

<14404.15166.862626.848917@kurtz.fake> Reply-To: FCC: sent

Version 3.5.3 is now available at and

The ChangeLog will follow, but please note the most important change: LZW compression has been removed.

Unisys has the patent on LZW compression and have been very active in their enforcement of late, demanding payments of $5000 or more from websites using unlicensed software to create GIF's. They could well do the same do persons using libtiff to create LZW compressed TIFF images.

From Burn All GIF's Day (

"The catch is that it appears to be difficult or impossible to get a Unisys license to use LZW in free software that complies with the Open Source Definition"

Unfortunatly, the compression removal means that saved image size has grown dramatically. Without a change in the TIFF spec to support another lossless compression format, this is unavoidable.

The library can use zip for lossless compression (thanks, Sam!), but as this is not part of the spec, TIFFs using zip compression may not work with other software.

We will be making a patch available that will contain the LZW compression code for users who have either obtained a license from Unisys or are willing to risk it.

LZW decompression is unchanged.


Tue Nov 30 14:41:43 1999  Frank Warmerdam  <>    ***3.5.3. release***

Tue Nov 30 09:20:16 1999  Frank Warmerdam  <>

        * Added some changes to tif_write.c to support rewriting existing
        fixed sized tiles and strips. Code mods disabled by default, only
        enabled if REWRITE_HACK is defined for now.

Mon Nov 29 11:43:42 1999  Frank Warmerdam  <>

        * Added TIFFWriteTile.3t man page.

Sun Nov 28 20:36:18 1999  Frank Warmerdam  <>

        * Added notes on use of in build.html, and fixed
        email subscription address.

199-11-28 Mike Welles <>

Sat Nov 27 16:49:21 1999  Frank Warmerdam  <>

        * fixed various VC++ warnings as suggested by Gilles Vollant

Wed Nov 24 12:08:16 1999  Frank Warmerdam  <>

        * Modified TIFFquery.3t man pages info on TIFFIsByteSwapped() to
        not imply applications are responsible for image data swapping.

1999-11-22 Mike Welles <>

1999-09-29  Mike Welles         <> 

M. L.  Welles