Atom modulus quantization for matching pursuit video coding
We provide an analytical study of the selection and modulus quantization of matching pursuits (MP) coefficients. We demonstrate that an optimal rate-distortion trade-off is achieved by selecting the atoms up to a dead-zone threshold, and by defining the modulus quantizer in terms of that threshold. In doing so, we take into account quantization error re-injection resulting from inserting the modulus quantizer inside the MP atom computation loop. In-loop quantization affects the stepsize of the uniform quantizer, and results in a non-uniform optimal entropy constrained quantizer. Improvements larger than one dB are obtained for video coding.