Motion estimation methods for overlapped block motion compensation

An extension of conventional block motion compensation (BMC), overlapped bl ock motion compensation (OBMC) has been shown to reduce residual errors and blocking effects in motion-compensated video. However, the overlap creates a non-causal spatial dependence between blocks and complicates motion esti mation (ME) for OBMC, Iterative methods have traditionally been employed fo r overlapped block motion estimation (OBME), For compression, the rate for the motion vector held (MVF) may also be constrained. This work considers s everal rate-constrained OBME algorithms, both iterative and noniterative. E xperiments demonstrate that a simple raster-scan algorithm is effective as a suboptimal, noniterative solution, with comparable or better rate-distort ion performance and computational complexity than iterative OBME algorithms . Depending on the application, either this method or a simple block-matchi ng algorithm plus iteration are the most attractive of the tested OBME sche mes.