Hello ajb, Wednesday, July 11, 2007, 7:55:22 AM, you wrote:
Not really. LZW is basically PPM with a static (and flat!) frequency prediction model. The contexts are build in a very similar way.
what you mean by "flat" and "static" applied to PPM? static PPM models exist - they carry probabilities as separate table very like static Huffman encoding. is "flat" the same as order-0?
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).
can you give a link? i never heard about such algorithm -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com