A Compression Technique Based on Optimality of LZW Code (OLZW)

A loss less dictionary based data compression technique has been proposed in this paper which is based on the optimality of LZW code. The compression process is started with empty dictionary and if the next symbol to be encoded is already in dictionary, length of symbol code is determined by the highest symbol code in the dictionary and encoded with the code in the dictionary. Otherwise, the symbol is encoded with 8-bit ASCII code. Some of the limitations of LZW compression technique have been eliminated in the proposed compression technique. Comparisons are made between proposed technique and two different version of LZW data compression technique which shows that the proposed technique works well for small size files particularly.