New concept of universal coding using one step reversible low contrast mapping (1RLCM)

Abstract

Universal coding was developed for compressing data that the probability distribution of a symbol is unknown. Universal coding methods encode a symbol using some bits as code based on the coding algorithm. This research introduces a new concept of universal coding by encoding two symbols using Reversible Low Contrast Mapping (RLCM) transform. The proposed method transforms a pair non negative integer to a non-negative integer and a binary number. This research also introduces a compression scheme namely Average Encoding (AE) to compress a sequence of data using the proposed coding method. This method generally yields a higher compression ratio than the Elias Delta, Elias Gamma, and Fibonacci coding when it is tested using the results of differential encoding of some testing images.