在低码率的网络视频通信中,数据包丢失往往导致整帧图像数据的丢失。为了修复丢失的整帧图像数据,提出了一种基于光流场不变性的整帧图像错误隐藏算法。该算法首先使用有理插值对前帧图像的运动矢量场做预处理来得到稠密的运动矢量场;然后采用前向投影技术将前一帧图像内容沿着运动矢量场方向投影到当前图像的对应位置上。由于在图像运动场的突变而形成的重叠和遮挡区域,该算法对其按前景和背景进行区分处理,因而进一步提高了错误隐藏的性能。实验结果表明,和已有算法比较,用该算法修复的图像的峰值信噪比提高了0.18~0.82dB,同时得到了更好的主观图像质量。

In low bit-rate packet-based video communications,loss of packet usually results in whole-frame losses.The algorithm dealing with the problem of whole frame loss is proposed in this paper.Rational interpolation is firstly applied to generate accurate dense motion field based on decoded block-based motion field.Then the previous image pixels are projected onto missing frame along the motion vector direction.The identification of overlapped and occluded areas is also used to improve error concealment performance.Experimental results show that the proposed algorithm outperforms other techniques in peak signal-to-noise ratio(PSNR) and provides good visual quality.