Predictive Enhanced Modified Orthogonal Search algorithm for wireless video sensor network

A wireless multimedia sensor network (WMSN) requires a video encoding system that should be energy-efficient because of its special characteristics: limited power source but long service life without maintenance. Motion estimation plays an important role in predictive coding, which is the key part of video encoding and requires large amount of calculation. In order to reduce the computational complexity of motion estimation, the block-matching search algorithm must be able to find the motion vectors using fewer search points. This paper introduces a search algorithm designed for WMSNs. It adds predictive search technique to the enhanced modified orthogonal search (EMOS) algorithm, which improves the efficiency of block-matching search algorithms, and has two self-adapting search patterns for large and small movements. The proposed algorithm requires less search points to work out the movement of blocks and provides acceptable image quality.