Fast global motion estimation based on iteration least-square estimation with sustained symmetrical structure

Global motion estimation (GME) plays an important role in a variety of video processing applications, such as content-based coding, coarse video segmentation, and mosaic. In this paper a novel fast global motion estimation algorithm based on iterative least square estimation (ILSE) is proposed for a four-parameter linear global motion model. The basic idea is to design rules to keep the symmetrical structure of processing units during iterative process, which can enormously reduce the computation load without impact on the estimation accuracy. The performance of the proposed fast-ILSE is analyzed and compared with traditional ILSE algorithm using sum of absolute difference (SAD) as criteria. Roughly about 50% addition operation is eliminated during calculation of zoom parameters, and 100% multiplying operation and 75% of adding operations are eliminated during calculation of pan parameters. And the proposed algorithm shows better estimation performance than the traditional ILSE method