基于邻近值的HEVC帧内预测优化

Optimization for HEVC Intra Prediction Based on Neighboring Pixels

高性能视频编码(High Efficiency Video Coding,HEVC)标准中的帧内编码模式利用当前帧中像素点之间的空间相关性作出有效预测。为了解决待编码像素远离参考像素时预测不准确的问题,提出了一种基于邻近值的HEVC帧内预测优化算法。该算法的主要思想是,对于当前像素,先根据传统HEVC帧内编码方法得到其预测值,再使用该像素点左边、左上、上边位置的修正值以及该像素本身的预测值对该预测值进行修正。因为将当前像素与周围像素的相关性进行了有效的数学建模,所以HEVC帧内编码性能得到了提升。实验结果显示,所提算法与HEVC标准相比,最高节省了2.7%的码率,平均节省的码率为1.3%。

The high efficiency video coding(HEVC)makes effective prediction by using the spatial correlation between pixels in the current frame.An optimization algorithm for HEVC intra prediction based on neighboring pixels is proposed to solve the problem of inaccurate prediction when encoding pixels are far away from the reference pixels.The main idea about this algorithm is that the predicted value of current pixel is firstly predicted according to the traditional HEVC intra prediction.Then the predicted value is modified by using the modified values of its left,upper left and upper positions as well as the predicted value of current position.Since the correlation between current pixel and its surrounding pixels is effectively modeled,the algorithm achieves efficient performance for HEVC.Experimental results show that,compared with the standard HEVC,the proposed algorithm achieves 1.3%bit saving on average and the highest up to 2.7%.