This paper presents a simulated annealing (SA)-based algorithm for fast and
robust block motion estimation. To reduce computational complexity, the ex
isting fast search algorithms move iteratively toward the winning point bas
ed only on a finite set of checking points in every stage. Despite the effi
ciency of these algorithms, the search process is easily trapped into local
minima, especially for high activity image sequences. To overcome this dif
ficulty; the new algorithm uses two sets of checking points in Every search
stage and invokes the SA to choose the appropriate one. The employment of
the SA provides the search a mechanism of being able to move out of local m
inima so that the new algorithm is less susceptible to such a dilemma. In a
ddition, two schemes are employed to further enhance the performance of the
algorithm. First, a set of initial checking points which exploit high corr
elations among the motion vectors of the temporally and spatially adjacent
blocks are used. Second, an alternating search strategy is addressed to vis
it more points without increasing computations. Simulation results show tha
t the new algorithm offers superior performance with lower computational co
mplexity compared to previous works in various scenarios.