基于功率谱的H.264/AVC快速帧内预测算法

Fast intra-frame prediction algorithm based on power spectrum for H.264/AVC

针对H.264/AVC帧内预测复杂度高的问题,结合H.264帧内预测的特点,提出一种基于功率谱的快速帧内预测算法。该算法在帧内预测之前,首先对宏块进行离散快速傅里叶变换,将频域内的三维功率谱函数转为化二维功率谱函数,然后利用二维功率谱函数的自相关性进行阈值判决,最后根据判决结果从两种预测模式中选择一种,从而减少算法的复杂度。实验结果表明,该算法在保证图像质量和编码码率较少增加的前提下,有效提高了编码速度;并且,该算法有利于在视频编码芯片上的实现,可用于实际的视频通信产品。

To solve the problem of high complexity in H. 264 / AVC frame prediction, in combination with the H. 264 intra-frame prediction characteristics, a fast intra-frame prediction algorithm based on power spectrum was proposed. Before coding, macrobloek was made discrete fast Fourier transform, and 3D power spectrum function in the frequency-domain were changed into 2D power spectrum function. And then according to the judging result on the threshold by correlation of 2D power spectrum function, one of the two prediction modes was selected. Therefore, coding time could be reduced dramatically. The experimental results show that the algorithm can increase the speed of intra coding significantly with negligible loss of PNSR and increase of bite-rate. Furthermore, the algorithm is prone to implement on video encoding chip, and can be used in practice.