Bounds on rate-distortion functions for stationary sources and context-dependent fidelity criteria (Corresp.)

A class of lower bounds to rate-distortion functions of stationary sources with context-dependent fidelity criteria is derived by mapping the source and distortion measure into an equivalent restricted-transition stationary source with a single-letter fidelity criterion, and then applying the composite bound. This approach is seen to yield bounds which, although sometimes quite loose, apply to general stationary sources and context-dependent fidelity criteria. Two examples are presented.