Frame interpolation based on bilateral motion refinement with rotation

Abstract

As new display system of LCD was developed, frame-rate up conversion (FRUC) is a useful technique to improve the temporal resolution in the display. FRUC converts the display format by interpolating intermediate frame between previous and current frame. In this thesis, a new frame-rate up conversion algorithm based on bilateral motion refinement with rotation is proposed. First, we propose the bi-directional motion estimation to obtain the accurate motion vectors for each block. Then, we apply the modified median filtering to motion vector field for outlier-rejection and motion field smoothing. Since these motion vectors are not obtained for intermediate frame, a refined motion estimation method is required in our algorithm. While most refined motion estimation algorithms adopt a method that uses a block-matching algorithm considering only translational motion, the proposed algorithm considers rotation in motion vector field. After the final motion vector with rotation is obtained, the intermediate frame is generated by applying the overlapped block motion compensation (OBMC). Experimental results show the proposed algorithm provides a better performance than the previous methods subjectively and objectively.