Robust error concealment for visual communications in burst-packet-loss networks

Compressed video sequences are very vulnerable to channel disturbances when they are transmitted through the burst-packet-loss networks such as a wireless channel. An effective solution for packet loss is to perform concealment at the receiver. Most of the spatial and/or temporal concealment methods estimate the true motion vector (MV) associated with a missing block by using the MV´s of the adjacent blocks. However, these methods cannot conceal effectively the missing blocks, since the neighboring blocks can be easily lost by the burst packet losses destroying a large area of coded video. In this paper, we present a robust error concealment method of estimating the true MV of the missing block by using the bidirectional motion tracking technique within neighboring frames of a damaged frame. This motion tracking technique uses the linear trajectory feature of the image block in the forward and backward prediction directions. Experimental results sow that the proposed algorithm has superior subjective and objective video quality than conventional error concealment methods in the burst-packet-loss environments.