The Research On Shape Error Concealment Based On Watermarking

The idea of object-based coding is a typical feature of MPEG-4 coding standard, and the binary shape Alpha plane of Video Object is the key for video coding and decoding correctly. Existent technologies of shape error concealment mostly estimate the error shape information according to some rules by using the shape information received correctly, but they cannot restore effectively the detail of shape information damaged seriously.Considering digital watermarking technology can embed the watermark into the host imperceptibly, the watermark can be transmitted depending on the host. The objective of this paper is to resume the shape information details with the interactive shape error concealment technology, which applies watermarking technology to the shape error concealment. The main work includes:(1) The existent various shape error concealment technologies are studied, classified and summarized. Through in-depth understanding the characteristics of digital watermarking technology, and the basic theory of shape error concealment based on watermarking are introduced, and a feasibility analysis is conducted.(2) A shape error concealment technology based on spatial domain watermarking algorithm is presented. The opening and closing operations in mathematical morphology are used to repair the extracted damaged watermark shape information, based on directional structural element developed in this paper. Then watermark shape information repaired is used to conceal the error in the binary shape Alpha plane. The results are compared with two existent methods, and the shortcomings existing in this technology are addressed.(3) Modified error concealment technology based on two transform domain watermarking algorithms, 2*2DCT watermarking and parity watermarking algorithm, is proposed, which can resist the shortage of the technology presented formerly. Then experiment results are compared and analyzed. Finally, the paper summarizes all the shape error concealment technology comparatively.The paper justifies, digital watermarking technology can be successfully applied to shape error concealment, and shape detail information damaged in the binary shape Alpha plane can be restored effectively.