<title>Hybrid block-matching algorithm for motion estimation</title>

Abstract

Motion compensation is a key operation in video compression to remove the temporal redundancy in a video sequence. One of the application examples is the MPEG video compression standard. The most commonly used motion estimation algorithm is the block matching algorithm due to its regularity. Full search is the most straight forward block matching algorithm which can always locate the optimal motion vector. However, its computational complexity makes it impractical in real time applications. Fast algorithm required less computation but the obtained motion vector is suboptimal. In this paper, a hybrid block matching algorithm is proposed. In this algorithm, average intensities of groups of pixels are used to roughly estimate the motion first. Then, the fast search algorithm is applied in a reduced search region centered around the result of the first pass. Experimental results show that the performance of the estimation accuracy is quite close to that of the full search algorithm while the computational complexity is only slightly increased with respect to those fast algorithms.