卫星视频帧内自适应误码掩盖新算法

Novel adaptive intra-frame error concealment algorithm for satellite video

在易发生错误的卫星信道的传输过程中,视频会产生误码和丢包.根据视频的边缘特征,将丢失块分成平坦块、边缘块和纹理块.然后,自适应地选择双线性内插、方向内插或者新方向加权内插作为内插方法,提高重构视频质量,加速误码掩盖过程.为了减少梯度计算量,将噪声像素从候选预测像素列表中剔除.为了准确地呈现图像的方向信息以及抑制噪声,选择Prewitt算子作为梯度滤波器.另外,使用分数像素内插来提高插值精度,适应高清视频应用.客观评价结果显示,在解码时间稍微增加的情况下,峰值信噪比大约提升了3dB.主观比较结果显示,提出的算法能够获得更高的视觉质量.

Bit error and packet loss exist during the transmission of video in the errorprone satellite channel.According to the edge feature in local video,each lost block is categorized as flat block,edge block,or texture block.Then bilinear interpolation,directional interpolation or novel directional weighted interpolation is adaptively selected as the interpolation method to improve reconstructed video quality and speed up the concealment process.Noise pixels are eliminated from the candidate prediction list to reduce the gradient computation.Prewitt mask is chosen as the gradient filter to accurately present the image directional information and restrain noise.Moreover,fractional pixel interpolation scheme is used to increase the interpolation precision and adapt the application of high-definition video.Objective evaluation shows that a peak signal to noise ratio(PSNR)improvement of up to about 3dB with negligible decoding time increment can be obtained.Subjective comparison shows that our proposed algorithm can achieve higher visual quality.