Watermarked Media Research Articles

Automatic Rotation Recovery Algorithm for Accurate Digital Image and Video Watermarks Extraction

Research in digital watermarking has evolved rapidly in the current decade. This evolution brought various different methods and algorithms for watermarking digital images and videos. Introduced methods in the field varies from weak to robust according to how tolerant the method is implemented to keep the existence of the watermark in the presence of attacks. Rotation attacks applied to the watermarked media is one of the serious attacks which many, if not most, algorithms cannot survive. In this paper, a new automatic rotation recovery algorithm is proposed. This algorithm can be plugged to any image or video watermarking algorithm extraction component. The main job for this method is to detect the geometrical distortion happens to the watermarked image/images sequence; recover the distorted scene to its original state in a blind and automatic way and then send it to be used by the extraction procedure. The work is limited to have a recovery process to zero padded rotations for now, cropped images after rotation is left as future work. The proposed algorithm is tested on top of extraction component. Both recovery accuracy and the extracted watermarks accuracy showed high performance level.

Survey on Reversible Watermarking

A number of research papers has been produced about reversible watermarking. Reversible watermarking is one of the important scheme of the watermarking schemes. Some security measures must be there to protect the records from unauthorized user and destruction of information. Basic idea of digital watermarking is to embed the data into the cover media to provide the security to data. The watermarking techniques satisfying these requirements called as Reversible watermarking. Ownership of the original media remains same but the best thing is original media is recovered from the watermarked media. This is the best and main feature of reversible watermarking to extract the original image as it is without any distortion. This feature is applicable in various areas such as medical as well as military images. If there is effect on the cover then it would changes the meaning of this data. The aim of this paper is to represent the purpose of reversible watermarking, some of the techniques related to reversible watermarking.

Content distribution and copyright authentication based on combined indexing and watermarking

Copyright issues become more and more urgent with the wide spread of multimedia content over Internet, e.g., whether the media content is copyright-protected in multimedia social networks, or whether a media content is released on Internet illegally. To solve these problems, this paper proposes a content distribution and copyright authentication system based on media index and watermarking techniques. Before media distribution, the media content is marked (by embedding the ownership information or customer identification into the media), and the robust features that can be used both for media index and content emendation is extracted from the watermarked media and registered in a feature database. Some customer may leak out his media copy over Internet directly or after slight operations, such as rotation, shearing, scaling, translation, etc. To detect whether a media over Internet is copyright-protected or not, the following work is done. Firstly, a watermark is extracted from the media and compared with the original one. If the watermark exists, then the media is copyright-protected, and the authentication process is finished. Otherwise, a robust feature is extracted from the considered media and matched with the feature database. The matching result gives the operation parameters that are used to emend the media content. After media emendation, a watermark is extracted or detected again and used to authenticate the copyright. In this system, the robust feature is not only used to search the related media contents but also to emend the media in order to improve the robustness against such operations as adding noise, compression, rotation, shearing, scaling, translation, etc. Experimental results show that the combination of media index and watermark detection can improve the detection rate greatly.

Reversible Watermarking: Current Status and Key Issues

Over the past few years a number of research papers about reversible watermarks has been produced. Reversible watermarking is a novel category of watermarking schemes. It not only can strengthen the ownership of the original media but also can completely recover the original media from the watermarked media. This feature is suitable for some important media, such as medical and military images, because these kinds of media do not allow any losses. The aim of this paper is to define the purpose of reversible watermarking, reflecting recent progress, and provide some research issues for the future.