Layer coder for hierarchical rate-distortion optimal coding of images
Stephan F. Simon, Bernd Huertgen · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1994
Hierarchical coding of images is often thought to require a higher bitrate than non-hierarchical coding. It is shown for a stationary, correlated Gaussian image source and the mean squared error fidelity measure that a hierarchical description can be achieved without additional rate. A coder model, based on the optimum forward channel, is developed which allows operating on the rate-distortion bound at every stage of the hierarchy. For the layer coders, of which the hierarchical system is composed, an explicit coding strategy is derived prescribing the amounts of rate required for spatial refinement and SNR refinement of already coded parts.