Adaptive motion estimation technique for motion compensated interframe interpolation

We propose a new fast motion compensated interframe interpolation algorithm. First, we propose a fast algorithm that obtains backward motion vectors by using forward motion vectors received from the transmitter. It is important to predict well both the covered and uncovered regions in order to interpolate skipped frames at the receiver, therefore, backward motion vectors are needed as well as forward motion vectors. But, in the case of the conventional video communication systems, we usually receive the forward estimated motion vectors from the transmitter. To estimate the backward motion vectors used to predict the uncovered region, the conventional interframe interpolation technique requires a large amount of calculation at the receiver because it uses exhaustive motion search such as full search block matching algorithm (FSBMA). In this paper, we reduce the computational complexity to get the backward motion vectors by using the dynamic search range varied for the forward motion vectors received from the transmitter. Second, we also propose the algorithm to obtain the motion vectors which are closer to the true object motion by utilizing the local characteristics of the vector field. This algorithm makes it possible, showing that the resulting motion vectors are more adaptive to the real object motion than the conventional one. According to the simulation results, the proposed algorithm is better than the conventional one in subjective quality as well as in objective quality.