Path map symbol release rules and the exponential metric tree [source coding]

To design a tree coder for source coding with a fidelity criterion, one must choose a suitable code generator, an efficient tree search algorithm, an appropriate distortion measure, and a path map symbol release rule. The performance of several path map symbol release rules when used with exhaustive searching of the exponential metric tree is investigated. The average single-letter distortion of fixed-length symbol release rules and two variable-length symbol release rules are derived for shallow search depths and compared to simulation results. The incremental or single-symbol release rule is shown to yield the best performance