Research On Prediction Technologies For Video Coding

With the development of digital video technologies, high definition and ultra high definition video get more and more widely applied, and more efficient video encoding technologies are in need. With the kick off of next generation video coding standard, many company and research organization proposed varieties high efficiency video coding technologies to make preparation of the next generation video coding standard. Among these new video coding technologies, prediction technology is a hot research topic. In this thesis, we focus on improving the motion compensation interpolation within inter-frame prediction and intra prediction. The result of the study shows that:1. This thesis proposed a design method for motion compensation interpolation filter. With this method which is based on the sampling feature of video signal, the coefficients of the interpolation filter can be obtained without the statistic of training video signal. The interpolation filter obtained by the proposed method can provide better compression efficiency (approximate 10% bitrate saving) than the one in the state in art video coding standard with the same interpolation precision for high definition video.2. This thesis proposed an improvement method of adaptive interpolation filter with filter coefficients buffering structure, which can eliminate the structure difference of the two encoding passes in adaptive interpolation filter encoding, and save the encoding bits of filter coefficients in some situation. In the decoder side with this method can use the same interpolation component to handle all interpolation requests, so the implement complexity of decoder can be reduced. This method proposed can improve the compression efficiency (approximate 1%~3% additional bitrate saving)of adaptive interpolation filter encoding for all test sequences.3. This thesis proposed a resolution converting method for intra prediction. This resolution converting method can reduce the distortion of resolution converting comparing with other method. With the proposed resolution converting method this thesis implemented down-sampling intra coding mode in the intra prediction code framework for the encoding of band-limited video signal. This down-sampling intra coding mode can improve the compression efficiency (approximate 4% bitrate saving) of intra coding for high defination video sequences.