Subband coding of video using energy - adaptive arithmetic coding and statisticalfeedback - free rate

An improved video subband coding technique is presented. It is based on a spatially and spectrally localizing subband analysis, followed by scalar quantization and direct arithmetic coding. The quantization and coding parameters are adapted on the basis of local energy of the subband pixels. The proposed technique automatically achieves near-optimal rate allocation with respect to mean-square error (or alternatively, weighted mean-square error). In addition, because arithmetic coding requires no alphabet extension, the quantized subband pixels can be encoded in an arbitrary order without aaecting bit rate. This makes it possible to obtain a good statistical estimate of the quantization resolution required to achieve a certain overall bit rate, based on a relatively small random sample of the subband pixels and their corresponding energies. The proposed technique requires that estimates of the local energy of the subband pixels be encoded and sent to the receiver as side-information. A means of accomplishing this, using vector quantization (VQ), is mentioned.