Error concealment algorithms for compressed video

In this paper we propose an error concealment algorithm for compressed video sequences. For packetization and transmission, a two layer ATM is utilized so that the location of information loss is easily detected. The coded image can be degraded due to channel error, network congestion, and switching system problems. Seriously degraded images may therefore result due to information loss represented by DCT coefficients and motion vectors, and due to the inter-dependency of information in predictive coding. In order to solve the error concealment problem of intra frames, two spatially adaptive algorithms are introduced; an iterative and a recursive one. We analyze the necessity of an oriented high pass operator we introduce, and the requirement of changing the initial condition in iterative regularized recovery algorithm. Also, the convergence of iteration is analyzed. In recursive interpolation algorithm, the edge direction of the missing areas is estimated from the neighbors, and estimated edge direction is utilized for steering the direction of interpolation. For recovery of the lost motion vectors, an overlapped region matching algorithm is introduced. Several experimental results are presented.