G'day all. Andrew Coppin wrote:
> > Actually, LZW works surprisingly well for such a trivial little > > algorithm... When you compare it to the complexity of an arithmetic > > coder driven by a high-order adaptive PPM model (theoretically the best > > general-purpose algorithm that exists), it's amazing that anything so > > simple as LZW should work at all! Not really. LZW is basically PPM with a static (and flat!) frequency prediction model. The contexts are build in a very similar way. Quoting Bulat Ziganshin <[EMAIL PROTECTED]>: > the devil in details. just imagine size of huffman table with 64k > entries :) If you're allowed to pick your code values, you can do this extremely compactly. Some compression schemes optimised for English separates words from the intermediate space and assigns a Huffman code to each word. The tables aren't that big (though the space to hold the words might be). Cheers, Andrew Bromage _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
