New Algorithms For Random Access Text Compression

Random access text compression is a type of compression technique in which there is a direct access to the compressed data. It facilitates to start decompression from any place in the compressed file, not necessarily from first. If any byte changed during transmission, the remaining data can be retrieved safely. In this paper, a try has been made to develop few algorithms for random access text compression based on the byte pair encoding scheme (Gage, 1997). The BPE algorithm relies on the fact that ASCII character set uses only codes from 0 through 127. That frees up codes from 128 through 255 for use as pair codes. Pair code is a byte, used to replace the most frequently appearing pair of bytes in the text file. Five algorithms are developed based on this byte pair encoding scheme. These algorithms finds the unused bytes at each level and tries to use those bytes for replacing the most frequently used bytes