Redundant Reduced LZW (RRLZW) Technique of Lossless Data Compression

Abstract

Technology is growing in every aspect but the basic needs to save the memory and time utilization still remains. Whenever we deal with any kind of data, we are bound to compress the data to minimize the space utilization. Data compression can be lossy or lossless. Some efficient lossless data compression techniques are Huffman coding, Run-length coding, Lempel- Ziv-Welch (LZW) coding. Lempel–Ziv–Welch (LZW) is a universal lossless data compression algorithm which works best on data with repeated patterns, so the initial parts of a message will see little compression. But LZW stores redundant string pattern which increase the number of entry of the dictionary thus increases the codeword size and this reduces performance of LZW technique. In this paper, a Reduced Redundant LZW (RRLZW) has been proposed to remove this redundant string pattern from the dictionary which increases the performance of LZW technique by decreasing the required memory to save data and also increasing the dictionary capacity. Also the performances of these algorithm and proposed system are measured and compared. The comparison shows that RRLZW performs better than LZW.

Keywords: Lossless compression, LZ77, LZ78, LZW.