2004.09.28 21:09 "[Tiff] TIFFTAG_PREDICTOR", by Ian Ameline

2004.09.28 22:52 "Re: [Tiff] TIFFTAG_PREDICTOR", by Joris Van Damme


In the docs at;


There is the strong implication that the predictor only does anything when using LZW compression.

I agree with Chris that the predictor stuff is an independent step in the encoding/decoding pipeline, and could be used with any compression scheme.

The reason why the text over at the predictor tag page is rather misleading, is that it is based on the TIFF 6.0 specification. Back then, Deflate wasn't yet around, and the use of the Predictor tag was much more de-facto tightly related to the use of the LZW compression scheme.

I'll see if I can rephrase the description on that page to a) more clearly state that it is independent of compression scheme, and b) state that it is nevertheless probably only usefull when combined with LZW or Deflate. Thanks for signalling this!

Joris Van Damme
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