B-picture coding with motion-compensated frame rate upconversion

Abstract

In this paper, we propose a new method to improve the coding efficiency of B-pictures by applying the motion compensated frame rate up-conversion technique. In B-Picture coding in H.264, the direct mode is used for one of the prediction modes. In the direct mode, B-picture is constructed without transmitted motion vector information. Therefore the direct mode is the most effective coding mode in B-pictures. On the other hand, in motion compensated frame rate up-conversion technique, interpolated frames which are similar to B-pictures, can be constructed with the motion vectors by detecting motion between coded images. In our proposed method, the same motion estimation algorithm is used for detecting motion vectors between coded P-pictures in both of encoder side and decoder side. Therefore, our proposed decoder can use the detected motion vectors without transmitted motion vector information for B-picture coding. In the experiment, we selected prediction modes for each block by using conventional rate distortion optimization algorithm. The proposed method provides B-picture coding efficiency nearly 30% over than that of H.264.