【摘要】 三维小波视频编码提供了分辨率、时域和质量的可伸缩性。在三维小波编码中,如何调整各小波频带间的码率分配以达到最佳的码率控制至关重要。就小波变换和反变换的结构而言,常规的三维小波视频编码方法会导致解码视频帧沿时间方向播放质量的周期振荡。这种周期的振荡会影响了观看质量。本文研究了重建信号与小波频带问失真分布的关系,提出了一种具有稳定的时域解码质量的率控制方法。实验结果表明该算法在保证播放质量稳定的同时,还具有与常规三维小波视频编码方法近似的平均解码质量。更多还原

【Abstract】 Embedded 3D wavelet video coding provides good spatial, temporal and scalable visual quality, These are very desirable features for adaptive video delivery and storage. The rate control problem in such video coder can be regarded as a problem of bit-allocation among different wavelet sub-bands. Considering the structure of wavelet analysis and synthesis, it is found that traditional 3D wavelet coders could potentially generate non-uniform distortions in the temporal domain of the reconstructed video data, and result in a periodic PSNR (quality) fluctuation across video frames. The periodicity of such PSNR fluctuation in the temporal domain may seriously influence visual perception. Accordingly, relationship between the distortion distribution in wavelet sub-bands and in the reconstructed data is investigated, and new rate control scheme capable of suppressing temporal fluctuation is proposed. Experimental results show that using proposed scheme, video quality in the temporal domain can be stabilized with considerable average PSNR compared with the 3D SPIHT and 3D EBCOT wavelet video coders.更多还原