2010.06.23 16:16 "[Tiff] LZMA2 codec for libtiff", by Andrey Kiselev

2010.06.23 16:16 "[Tiff] LZMA2 codec for libtiff", by Andrey Kiselev

Folks,

I've just added an experimental LZMA2 codec for libtiff. The patch is available at

 http://bugzilla.maptools.org/show_bug.cgi?id=2221

and should be applied to CVS HEAD (i.e. libtiff 4.0). You need an SDK from

 http://tukaani.org/xz/

which is available in many Linux distributions as liblzma package. All interested parties are welcome to test this stuff. Tiffcp should understand a '-c lzma' option after appling the patch (it was done for tiffcp only so far). Predictor also could be used, though the codec itself utilizes the delta data filter.

After some testing it could go into libtiff.

LZMA codec has some pros and cons. It lacks a proper specification of the encoded stream, it is processor and memory hungry. On other hand the implementation (liblzma) is public domain and seems to be patent free (though you can never be sure). Compression is better than the one with Defalte codec for almost all data files I've tried. Sometimes it is MUCH better.

Best regards,
Andrey

--
Andrey V. Kiselev