[Gdal-dev] packbits compression no good for 16bit?

Matt Wilkie matt.wilkie at gov.yk.ca
Wed Feb 7 11:40:55 EST 2007

> I believe that packbits compression is applied byte by byte.  If your
> nodata areas use a 16bit value where the high order and low order byte
> are different then there will essentially be no "runs" for the packbits
> compression scheme to compress.  I think you would find it does a great
> deal better if your nodata value was something like 0.
> Packbits is very simple minded.

Thank you for the peek under the hood. At least I have an idea of what 
is (not) happening now. I'll stick with lzw compression for now.

matt wilkie
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Information Management and Technology,
Yukon Department of Environment
10 Burns Road * Whitehorse, Yukon * Y1A 4Y9
867-667-8133 Tel * 867-393-7003 Fax

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