2010.06.25 10:09 "Re: [Tiff] LZMA2 codec for libtiff", by Andrey Kiselev

On Thu, Jun 24, 2010 at 10:54:57AM -0500, Bob Friesenhahn wrote:

On my typical data it is much worse than LZMA. Actually I do not see a reason to use it because of worse compression ratios. I am talking about libtiff usage here, of course bzip2 utility is widely adopted as a general purpose compressor and LZMA stuff is not on par here.

When you compared LZMA with bzip2, did you do it by compressing whole image files? What type of images are you testing with?

ImageMagick and GraphicsMagick support bzip2 compression in the "MIFF" file format. Compression is done on a per-row basis without any modification via a 'predictor'. This makes it a good test case for bzip2 compression.

I've compressed the raw raster image, pixel interleaved. And I've used the delta filter supported by LZMA codec. Without the data preparation results are not such impressive, yes.

Best regards,
Andrey

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Andrey V. Kiselev