Multimedia Authentication Oriented Watermarking

With the aid of sophisticated photoediting software and rapid development of social networking,multimedia content security is prominent due to its easy-tamper property.Digital watermarking technique embeds additional information into the multimedia based on its redundancy,which provides effective technical support for the copyright authenticity and integrity identification in network environment.Aiming at authentication oriented digital watermarking,we focus on three difficult aspects,i.e.low capacity for reversible watermarking,poor recovery quality for recoverable watermarking and the high dimension data watermarking.The main works are summarized as follows:(1)Reversible Watermarking based Authentication: For the lower capacity limitation of current reversible data watermarking,we propose an integrity authentication oriented separable reversible data hiding algorithm for encrypted images with high capacity.When the receivers accept an encrypted image containing additional data,the processing procedure depends on the role of receiver.If the receiver only has the data hiding key,he can extract the data without knowing the image content.If the receiver only has the encryption key,he can decrypt the image with a better quality.If the receiver has both of two keys in such case.Thus,the data extraction and content recovery are all done,and both results are free of error.(2)Recoverable Watermarking based Authentication: Aiming at the recovery issue of current image authentication methods,we address the problem of semi-fragile image tamper localization and self-recovery with sparse signal recovery.Specifically,two watermarks,which can be regarded as image integrity and host content representations,are adopted for authentication and recovery.Our algorithm has the ability to identify tamper regions at pixel-level,and recover the content modifications,even under incidental manipulations.Extensive experiments demonstrate the effectiveness of the proposed scheme,which is sensitive against malicious tamper and robust to incidental manipulations,such as JPEG compression,slight noise addition,brightness/contract adjustment and format conversion.(3)Watermarking based Authentication for High Dimension Data: For the copyright protection of 3D motion data,we present a blind robust watermarking mechanism based on maxima curvature.The mechanism segments motion data based on stable anchor-points captured by the maxima in spatio-temporal curvature and filtered by posterior attack model.For each segment,we make a randomized cluster division of 3D points based on a secret key.A watermark is then embedded within these clusters by Triangle Orthocenter based encoding approach.Experimental results show that the proposed scheme is robust against many possible attacks such as uniform affine transforms(scaling,rotation and translation),noise addition,reordering and cropping.