(S,C)-Dense Coding: An Optimized Compression Code for Natural Language Text Databases.

Nieves Brisaboa, Antonio Fariña, Gonzalo Navarro and María Esteller

This work presents (s,c)-Dense Code, a new method for compressing natural language texts. This technique is a generalization of a previous compression technique called End-Tagged Dense Code that obtains better compression ratio as well as a simpler and faster encoding than Tagged Huffman. At the same time, (s,c)-Dense Code is a prefix code that maintains the most interesting features of Tagged Huffman Code with respect to direct search on the compressed text. (s,c)-Dense Coding retains all the efficiency and simplicity of Tagged Huffman, and improves its compression ratios.

We formally describe the (s,c)-Dense Code and show how to compute the parameters s and c that optimize the compression for a specific corpus. Our empirical results show that (s,c)-Dense Code improves End-Tagged Dense Code and Tagged Huffman Code, and reaches only 0.5% overhead over plain Huffman Code.