COMPARATIVE STUDY AND ANALYSIS OF ADAPTIVE REGION BASED HUFFMAN COMPRESSION TECHNIQUES

In this paper, the comparative studies of Adaptive Region Based Huffman compression techniques are done. All these techniques use a region formation algorithm that is also discussed. This algorithm is used to form regions whose size is adjusted depending on the ASCII value difference of elements in the file. One of the techniques is Size Adaptive Region Based Huffman Compression (SARBH) where Huffman codes for entire file are obtained after formation of regions to encode elements of the files. Another technique known as Size Adaptive Region Based Huffman Compression with code interchanging (SARBHI) where interchanging of codes are done between the maximum frequency element of a region and maximum frequency element of entire file before elements of that region are compressed. Another variation of the technique is Size Adaptive Region Based Huffman Compression with selective code interchanging (SARBHS) where region wise interchanging of code is done based on an additional condition. Comparisons in terms of compression ratios and compression times are made among these three techniques and also with Region Based Huffman compression technique and classical Huffman technique. The proposed techniques offer better rates of compression for most of the files. Among these techniques, SARBHS is more effective for all most all types of files.