On the average redundancy rate of adaptive block codes under mixed sources

Summary form only given. The average redundancy rate of Krichevsky's sample-based universal block codes was analyzed, in a situation wherein the samples and block codes for compression were produced from two different memoryless sources. It was proven that the average redundancy rate of adaptive block codes O/sub /spl lscr/,T/, constructed using samples of length /spl lscr/ from a source T, were used to encode block codes of length n from a source S. The adaptive block codes, constructed using samples from a source T and applied to a source S, have achieved lower average redundancy than universal codes.