Fast motion vector search for overlapped block motion compensation (OBMC)

Abstract

The overlapped block motion compensation (OBMC) scheme provides an effective way to reduce block artifacts in video coding, and is adopted as an optional mode in the H.263 standard. However the motion vector search complexity increases significantly due to the motion interdependency of OBMC. In this work, we present a new OBMC motion vector search algorithm which reduces the computational complexity while preserving the decoded video quality. Unlike other iterative algorithms previously developed, our proposed algorithm requires no iteration during the motion vector search process. Furthermore, a fast search algorithm is adopted to reduce the search complexity. It is demonstrated by extensive experimental results that the proposed algorithm reduces a substantial amount of complexity and achieves a similar PSNR result in comparison with the existing iterative methods.