BWT-based Data Preprocessing for LZW

In this paper we propose a BWT-based LZW algorithm for reducing the compressed size and the compression time. BWT and MTF can expose potential redundancies in a given input and then significantly improve the compression ratio of LZW. In order to avoid the poor matching speed of LZW on long runs of the same character, we propose a variant of RLE named RLE-N. RLE-N does not affect the compression ratio, but it contributes LZW to reduce the execution time obviously. The experimental results show that our algorithm performs well on normal files.