Bayesian error concealment with DCT pyramid

In this paper, the problem of concealing missing image/video blocks is casted into a framework of Bayesian estimation. The conditional expectation of the missing block vector is taken over a pilot vector of correctly decoded pixels near the missing block. Multiple observations of the missing vector and pilot vectors obtained in a nonlocal manner are used to approximate the expectation. We design a multiscale estimation approach with DCT pyramid to improve estimation efficiency. The DC image of the missing block is recovered first, and then more details related to high frequency AC coefficients are recovered successively. The algorithm is found to be quite competitive among state-of-the-art, and more substantial improvement over existing algorithms on image with heavy loss rate/large block size is observed in our experiments.