Directional Smoothness Constraint Based Error Concealment

Abstract

Video signal is a highly compressed signal due to the restricted bandwidth of the Network. However, the compressed bitstreams are very sensitive to channel errors. In this work, a novel algorithm is presented for repairing damaged DCT coded images while decoding/transcoding an error bitstream. The algorithm first estimates the edge direction in a damaged block by considering edge features in its neighborhoods, where the features in each neighborhood are detected by only using two low frequency DCT coefficients in the block. And then the damaged block is reconstructed under smoothness constraint along the edge direction. Experimental results demonstrate that the proposed algorithm can obtain better subjective and objective quality than conventional algorithm.