Error Concealment using Motion Field Interpolation

In the context of block-based video coding, two error concealment algorithms are presented. The first algorithm is based on bilinear motion field interpolation (BMFI). For each pel in a damaged block, the algorithm recovers a motion vector using bilinear interpolation of neighbouring motion vectors. This vector is then used to conceal the damaged pel. A reduced complexity version of this algorithm is also presented. The second algorithm uses overlapped motion compensation to combine the first algorithm with a boundary matching error concealment algorithm. Simulation results show that at low error rates the first algorithm outperforms other concealment techniques, but its performance starts to deteriorate with increasing error rate. The second algorithm, however, maintains a superior performance regardless of the error rate. Simulation results within an H.263 codec are also presented. concealment which provides a subjectively acceptable approximation of the original data by exploiting the high temporal and spatial correlation of video sequences. This approach requires no change to the encoder and no increase in the bit rate. It is particularly attractive for very low bit rate applications. In this paper we propose a temporal error concealment method based on bilinear motion field interpolation (BMFI). The paper is organised as follows. Section 2 briefly reviews a number of temporal error concealment methods and discusses their drawbacks. Section 3 describes the BMFI error concealment method and highlights its main advantages. Section 4 discusses ways of reducing the complexity of the BMFI method. Section 5 shows how to use overlapped motion compensation to combine the BMFI method with a boundary matching method to achieve a more robust error concealment method. Section 6 presents the results of testing the proposed algorithms. Finally, section 7 gives some concluding remarks.