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March 2006
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2006.03.04 06:27 "Re: LZW Compression with 16-bit TIFF", by Bob Friesenhahn
> > 16 bit data can be difficult to compress. Have you tried enabling > > horizontal differencing? > > > > TIFFSetField(tiff,TIFFTAG_PREDICTOR,2); > > Why should 16-bit data be any different in principle that 8-bit > data? A change in data length should not have any bearing on > compression (at least that's what I would first think). The more levels available, the more difficult the data is to compress. That is due to less opportunity for repeated codes. > As for horizontal differencing, supposedly that's what the "-c lzw:2" > option accomplishes. Is there another way to enable this by setting > some parameter in the source code and then recompiling? The line of code that I posted? :-) Bob ====================================== Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/