Coding by selective prediction: a new scheme for predictive vector quantization
Typically, predictive vector quantization is performed by making a prediction of upcoming data based on previously coded samples, then, using a residual quantizer to code the prediction errors. We take in alternative approach, and introduce coding by selective prediction (CSP). In CSP, there is no residual quantizer - the codebook consists only of a collection of predictors. The encoder selects the predictor that best describes a source block, then transmits the index of that predictor. We give a framework for CSP, then propose a training method for codebook design, similar to the generalized Lloyd algorithm. Using fixed-rate coding, performance results for CSP as an image coder indicate a 0.5 dB improvement over conventional predictive vector quantization at equal rates.