Variable length to block coding

Abstract

We treat the problem of encoding the outputs from an information source, and the class of encoding schemes considered is restricted to those in which each output from the source is encoded as a separate, uniquely decodable codeword. We present a uniquely decodable scheme in this class which minimizes the ensemble average length of the transmitted message. The efficiency of this method in some cases is higher than conventional methods like block coding (in this paper we call it "block to variable length coding" relative to the title of the paper) by using the Huffman method. Although the efficiency of the encoding scheme can be improved by using the variable length to variable length technique, this topic is not pursued