为了提升可分级视频编码的层间帧内预测(ILIP)性能,提出了一种基于维纳滤波器的块级别自适应ILIP方法.首先,将一帧图像分块;其次,逐块选取原始增强层图像和对应的基本层上采样图像逐帧进行训练,得到维纳滤波器系数;最后,采用获取的滤波器系数对基本层上的采样图像进行滤波,并在块级别加以控制,以便降低预测误差能量.实验结果表明,与传统ILIP方法相比,新方法可以获得更精确的预测结果,编码器输出比特率下降最高可达14.45%.
In order to improve the performance of inter-layer intra prediction (ILIP) in scalable video coding, a Wiener filter based block level adaptive ILIP method is proposed. Firstly, the frame to be coded is divided into a number of blocks. Afterwards, the Wiener filter coefficients are obtained by a frameby-frame training procedure, in which both of the enhancement layer (EL) signal and the corresponding up-sampled base layer (BL) signal are utilized. Finally, the achieved Wiener filter coefficients are applied to optimize the up-sampled BL signal, and a block level filter control is introduced to reduce prediction error energy. Experiments show that, compared with the traditional ILIP method, the proposed method can get more accurate prediction of the EL signal, resulting in up to 14.45% encoding bit rate reduction.