Motion-Compensated Frame Rate Up-Conversion—Part II: New Algorithms for Frame Interpolation

Motion-compensated frame rate up-conversion (MC-FRUC) consists of two key elements: motion estimation and motion-compensated frame interpolation. The motion estimation algorithm presented in , which is used in the MC-FRUC method proposed in this paper, provides unidirectional motion trajectories. The advantage of this motion estimation algorithm, besides its accuracy, is that it provides information on occlusions. However, motion compensation along unidirectional motion trajectories yields overlaps, holes, and blocking artifacts. To solve these problems, this paper presents two new algorithms for unidirectional motion-compensated frame interpolation: irregular-grid expanded-block weighted motion compensation (IEWMC) and block-wise directional hole interpolation (BDHI). The IEWMC is used to reduce the blocking artifacts and solve the problem of overlapping blocks. The BDHI preserves local texture and edges while filling holes. Experimental results show that the IEWMC outperforms conventional motion compensation, and the BDHI is better than the repeated median filter that is often used to fill holes. The performance of the proposed MC-FRUC, that uses the two new algorithms and the unidirectional motion estimation algorithm, is evaluated against three existing MC-FRUC techniques: a typical bi-directional algorithm, an object-based algorithm, and a commercial plug-in product. Experimental results show that the quality of the pictures interpolated using the proposed MC-FRUC method is much higher than those interpolated using the three existing MC-FRUC techniques.