2010.12.22 16:20 "[Tiff] [ANNOUNCE]: LZMA2 codec", by Andrey Kiselev

2010.12.23 10:57 "Re: [Tiff] [ANNOUNCE]: LZMA2 codec", by Andrey Kiselev

On Wed, Dec 22, 2010 at 05:38:46PM -0700, Scott Ribe wrote:

I would like to announce that the code implementing LZMA2 compression has been checked in the libtiff's development branch (4.x). tiffcp utility can utilize this new compression method (use '-c lzma' switch). Encoder applies delta filter internally, but you still can use predictor value 2 or 3. Sometimes it helps to get even better compression ratios. LZMA2 seems to be the best comression method (comparing to LZW and Defalte), though the slowest one. Worth a try if you are hunting for bytes.

That's interesting, is there something like a how-to you could point me toward for adding bzip the same way?

There is no any documentation on that, but the code is pretty much self-explanatory. Take a tif_zip.c or tif_lzma.c as a template. Also you can take a look at the whole patch adding LZMA support:

 http://bugzilla.maptools.org/attachment.cgi?id=400&action=diff

to get an idea what parts of libtiff are being affected by the new codec. LZMA SDK maintains the API similarity to zlib, so it is a straitforward task to adopt tiff_zip.c to it. I think that bzip2 library should be similar too.

Best regards,
Andrey

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Andrey V. Kiselev