Sparse Recovery-Based Error Concealment

Abstract

Image and video transmission over heterogeneous networks may encounter packet loss due to the channel impairments, leading to quality degradation of the received image. In this paper, a novel robust image transmission system is proposed by casting the error concealment challenge into a sparse recovery framework. To this purpose, a robust encoder is carefully designed in order to mitigate the negative effects of the packet loss. After wavelet decomposition, a quadtree structure of the wavelet coefficients is used to rearrange them into independent partitions. Random linear combinations of coefficients for each partition are then adopted to provide a high error recovery capability. This linear process coupled with a simple packetization process introduces more robustness and error resilience into the transmission system. At the receiver side, the tree-sparse structure of the wavelet coefficients is explicitly exploited in order to model the error recovery problem as a sparse recovery framework. This is achieved by adaptation of a well-known iterative sparse reconstruction algorithm to the defined tree structure built in the wavelet domain. Compared with the state-of-the-art error concealment algorithms, experimental results show that the proposed method has better reconstruction performance in terms of objective and subjective evaluations over a range of packet loss rates, and ensure that a high-quality image can be recovered for the high packet loss scenarios.