In this paper, we propose a non-Delaunay hierarchical mesh-based motion estimation and compensation technique over the spatial domain for wavelet video coding. In particular, we concentrate on reducing high-band signals and corresponding motion estimation errors in order to improve coding efficiency. We also analyze the trade-off between rate-distortion and computational complexity with a variety of video test sequences. Finally, experimental results show that a non-Delaunay hierarchical mesh-based method can give good performance at low computational complexity in a wavelet video codec.

ARMI is a communication library that provides a framework for expressing fine-grain parallelism and mapping it to a particular machine using shared-memory and message passing library calls. The library is an advanced implementation of the RMI protocol and handles low-level details such as scheduling incoming communication and aggregating outgoing communication to coarsen parallelism when necessary. These details can be tuned for different platforms to allow user codes to achieve the highest performance possible without manual modification. ARMI is used by STAPL, our generic parallel library, to provide a portable, user transparent communication layer. We present the basic design as well as the mechanisms used in the current Pthreads/OpenMP, MPI implementations and/or a combination thereof. Performance comparisons between ARMI and explicit use of Pthreads or MPI are given on a variety of machines, including an HP V2200, SGI Origin 3800, IBM Regatta-HPC and IBM RS6000 SP cluster.