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Date: Fri, 3 Mar 2006 22:33:40 -0500
From: Frank Peters <frank.peters@comcast.net>
To: tiff@lists.maptools.org
Subject: Re: [Tiff] LZW Compression with 16-bit TIFF
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Status:   

On Fri, 3 Mar 2006 21:12:17 -0600 (CST)
Bob Friesenhahn <bfriesen@simple.dallas.tx.us> wrote:

> 
> 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).

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?

Frank Peters

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