摘要
针对AVS(Audio Video Coding Standard,音视频编码标准)视频部分帧内预测中固定三抽头滤波器难以适应纹理类型变化、预测精度低的问题,基于相邻一维数据块(像素行或者像素列)之间纹理一致性更强的特点,提出了基于一维数据块的帧内自适应滤波编码算法,将固定三抽头滤波器扩展为自适应滤波器,以一维数据块为单位生成预测,解决参考像素与预测像素之间距离较远所带来的相关性差、预测不准确的问题。利用最小二乘方法,对已编码的相邻一维数据块进行自适应滤波预测,计算得到最优的三抽头滤波器,将其直接作为当前一维数据块的自适应滤波器,从而避免了自适应滤波器系数的传输开销。实验结果表明:新的帧内编码方法能够提高现有AVS视频帧内编码效率平均达到0.324 dB,最高达到0.879 dB,而且编码性能高于帧内模板匹配方法平均0.120 dB。所提出的方法在新一代的视频编码标准AVS2.0的制定中具有广阔的应用前景。
The fixed 3-tap filter in AVS intra prediction cannot adjust to various textures well, resulting in low coding efficiency of intra coding. Considering that texture consistency of adjacent samples is much stronger, adaptive filtering prediction based on one-dimensional block is proposed. In the novel algorithm, the sample row or column is taken as the coding unit instead of 8x8 sample block, and adaptive 3-tap filter is applied to covering various texture orientations, solving the problem of weak correla- tion which is caused by the long distance between predicted and predicting samples. To avoid the transmitting cost of adaptive filter coefficients, the adjacent coded one-dimensional sample block is taken as the target block and its adjacent block as the source to generate prediction, and via least square method, it＇ s easy to obtain adaptive filter coefficients which are directly facili- tated to the coding of current one-dimensional sample block. Experimental results show that the novel intra coding method out- performs conventional intra coding in AVS video by an average of 0.324 dB with maximum of 0.879 dB. The adaptive intra fil- tering coding based on one-dimensional block can get a stable gain of average 0.120 dB compared with intra coding based on template matching prediction. The novel intra coding method demonstrates a good potential in future AVS 2.0 standard.
出处
《计算机工程与应用》
CSCD
2013年第15期224-228,共5页
Computer Engineering and Applications
基金
国家自然科学基金(No.61003184)
中国电子科技集团公司技术创新基金项目(No.JJ120202)
