The Research Of Error Concealment For MPEG-4 Video Image

As video coding is very sensitive to channel disturbances due to the use of compression algorithm. Therefore, error concealment techniques are becoming increasingly important for getting high quality video image.Recently MPEG-4 has been widely used. Various methods have been proposed for error concealment of texture information, but these methods can't be used to error concealment of shape information. Whereas shape information is an important part of MPEG-4 coded bit stream. Therefore this paper mainly presents the research of error concealment of shape information.Firstly, we introduce the basic methods of error concealment. These methods can be divided into three species: forward error concealment,error concealment by post-processing at the decoder and encoder and decoder interactive error concealment.Secondly, we analyze statistical method for error concealment. This method can get well-reconstructed image, but its calculation is complex and it has obvious block domino offect. Therefore this paper adopts an error concealment method by post-processing at the decoder, which is based on Bezier curve and curve fitting. Experiment results demonstrate that this method is effective.At last, considering global motion compensation, this paper adopts a forward error concealment method, which is based on global motion compensa- tion. Experiment results demonstrate that this method is effective and excellent, especially when the whole object is lost,the shape information's lost area is large or the lost part is complicated..