A Low-Complexity Image Registration Algorithm for Global Motion Estimation

An important recent application of image registration is the estimation of global motion parameters for object-based video coding. However, the main disadvantage of standard approaches to global motion estimation (GME) is the increased computational complexity with the higher degree of motion models when compared to block-based local motion estimation approaches. In this paper, we propose a new low complexity GME algorithm. In our proposed algorithm, full-precision images are replaced with 1 bit-per-pixel images which allows many of the arithmetic operations in the standard GME approach to be replaced with logic operations. Experimental results show that our proposed algorithm achieves the same registration accuracy as the standard GME approach but with significantly reduced computational complexity. Our results also demonstrate the superior performance of the proposed algorithm when compared with previously proposed low-complexity GME approaches.