Frame-rate conversion using hybrid-search-based motion estimation and adaptive motion-compensated interpolation

Abstract

We propose a frame-rate conversion algorithm using hybrid-search-based motion estimation (ME) and adaptive motion-compensated interpolation (MCI). The ME method uses three search strategies: recursive search, three-step search with predictions, and single predicted search. One of them, which is best suited for the predicted motion type, is adaptively performed on a block basis. This adaptation process improves the accuracy of the estimated motion vectors without increasing the computational load. With the estimated motion vectors, the proposed MCI method reconstructs high-quality frames, without producing block artifacts, by considering multiple motion trajectories. The method utilizes pixel smoothness constraints besides motion-vector reliability when creating and combining the multiple motion-compensated results to remove block artifacts in regions with unreliable motion vectors. Experimental results show that the proposed ME method produces reliable motion vectors that are closer to true motions. Also, the proposed MCI method achieves better image quality than existing algorithms.