Rate distortion analysis of subband motion compensation for video spatial scalability

In this paper, we derive the rate distortion performance lower bound of the subband motion compensation technique which exploits both the inter-layer spatial and intra-layer temporal redundancies for video spatial scalability. The lower bound is derived by rate distortion theory for stationary Gaussian signals where mean square error (MSE) is used as the distortion criteria. Assuming that the base layer is encoded by an optimal non-scalable video coder, the rate distortion function derived for the enhancement layer depends on only the power spectral density (PSD) of the input signal, the motion prediction error probability density function (p.d.f.) and the base layer encoding parameter. Our evaluations will show that, if base layer is encoded at a relatively high quality, subband method is expected to outperform simulcast, where spatial layers are encoded independently, in terms of rate distortion efficiency.