  With the rapid growing of data and number of applications, there is a crucial
need of dictionary based reversible transformation techniques to increase the
efficiency of the compression algorithms and hence contribute towards the
enhancement in compression ratio. Performance analysis of compression methods
in combination with the various transformation techniques is obtained for
different text files of varying sizes. The popular block sorting lossless
Burrows Wheeler Compression Algorithm (BWCA) is implemented along with one
proposed method. For efficient compression a dictionary based transformation
algorithm is also developed. It is observed that much increase in terms of
compression ratio is attained when a source file is preprocessed with
dictionary and then applied to BWCA and the proposed method.
