Fast Global Motion Estimation

Global motion estimation (GME) plays an important role in many video application systems such as video coding system MPEG-4. However, its computational complexity is very high. Fast algorithms are needed. In this paper, we propose an improvement to the GME algorithm. We achieve this by introduce two techniques. Firstly, integral projection algorithm (IPA) is used to get first translation estimation and reduce block matching algorithm (BMA) search range. Secondly, coarsely block sampling technology directly reduces the computation complexity. GME composite performance experiments prove that our GME method only degrades -0.13 dB in PSNR compared with the MPEG-4 verification model (VM), while it gets a 5.93 ms per frame speed and is 73.3 times faster than the VM. Global motion compensation (GMC) coding experiments also show no loss of GME accuracy and compression efficiency compared to the MPEG-4 VM GME method.