A Modified Approach to Huffman Algorithm for Unequal Bit Costs

Classical Huffman coding creates variable length code for data compression. It has very good performance over data compression for many current systems. The goal of the Huffman algorithm is to encode a set of characters given their frequencies over a given alphabet. To keep the code decodable the encoding needs to be prefix free. But better encoding is possible if we consider different cost for different symbols of the alphabet. In the case of binary encoding it is obvious that the costs of one and zero are never same while transmitting data. If different bits can be considered differently then transmission system can become more efficient. Hence, different encoding scheme using unequal bit cost would be necessary. This study proposes an algorithm for data compression where different cost for different bit is considered. Our experiment shows that our algorithm has a better performance than classical Huffman coding in terms of total cost while compressing data. Our variant of Huffman algorithm can give better performance for transmission, storage, speed of execution and so on.