Concealment of visual effects of image transmission errors by a sketch-based recovery approach

The problem of masking unpleasant visual effects caused by data loss during image transmission over a packet network is addressed. Due to the widespread use of block-based algorithms in image coding, such loss results in a block or sequence of blocks missing in the decoded image. In order to improve the quality of the image subject to cell or packet loss, appropriate concealment algorithms can be satisfactorily applied. The technique proposed is based on a sketch representation of the visual information associated to the high-frequency content. The proposed method has been applied with good results in the transmission of both video and still pictures