A BIT-LEVEL TEXT COMPRESSION SCHEME BASED ON THE HCDC ALGORITHM

摘要

In this paper we proposed and evaluated the performance of a new bit-level text compression scheme that is based on the Hamming codes based data compression (HCDC) algorithm. The scheme consists of six steps some of which are repetitively applied to achieve higher compression ratio. The repetition loops continue until inflation detected and the accumulated compression ratio is the multiplication of the compression ratios of the individual loops, therefore, we refer to the new scheme as HCDC(k), where k refers to the number of repetition loops. To enhance the compression power of the HCDC(k) scheme, a new adaptive encoding format was proposed in which a character is encoded to binary according to its probability. This method of encoding reduces the binary sequence entropy so that it grants higher compression ratio. A number of text files from standard corpora were compressed and the obtained results demonstrated that the proposed scheme has higher compression power than many widely used compression algorithms and it has a competitive performance with respect to state-of-the-art programs.