多功能水印在数字图像版权保护中的应用

数字水印是信息隐藏技术的一个重要分支,是一种全新的数字产品保护技术。多功能水印克服了传统数字水印的不足,将多个功能水印嵌入到载体中,具有版权保护、用户跟踪和内容完整性认证三种功能。本文介绍了多功能水印的基本原理,并对典型的多功能水印算法进行了阐述。最后.分析指出了多功能水印技术的研究现状与发展前景。     

基于小波域的自适应图像水印算法

多媒体信息的数字化极大地提高了信息表达的效率和准确性,随着网络技术的快速发展,数字媒体的传播变得更加方便和快捷,但同时盗版和侵权的问题也日益严重,数字水印技术作为一种数字媒体版权保护的有效方法近年来引起了人们的高度重视.提出一种基于小波变换的自适应图像水印算法,该算法利用了人类视觉系统的特性,根据图像分块扫描序列中两相...     

Contrast-Adaptive Removable Visible Watermarking (CARVW) mechanism

Engineers have proposed many watermark mechanisms for protecting the content of digital media from unauthorized use. The visible watermark scheme indicates the copyright of digital media posted over the Internet by embedding an inconspicuous but recognizable pattern into media. However, the embedding process often results in serious distortion of the protected image. Since the strength of the watermark in conventional methods mainly depends on the feature of protected media, this may lead to unsatisfactory transparency of watermarked images. This paper proposes a removable solution for visible watermark mechanism. By adopting the subsampling technique, the method proposes a contrast-adaptive strategy to solve this problem. This method can also guarantee the essentials of general visible watermark schemes. Experimental results show that the proposed method outperforms related works in terms of preserving the quality of the restored image.     

VRML animated model watermarking scheme using geometry and interpolator nodes

Distinct from image and video watermarking, a watermarking scheme for 3D animation content is required in the 3D industry market for various applications. This paper develops a watermarking scheme for copyright protection and authentication of 3D animation content. A 3D animated model generally has a hierarchical structure with a number of transform nodes of a geometry node and an interpolator node for the timeline in contrast to a 3D polygon mesh model. The proposed scheme embeds not only a robust watermark into the geometry node for copyright protection but also a fragile watermark into the position and orientation interpolators for content authentication. We named the former “robust geometry watermarking” and the latter “fragile interpolator watermarking”. The proposed scheme performs the two watermarking schemes independently to realize simultaneously robust and fragile watermarked 3D animated model. Experimental results confirm that a watermark embedded by geometry watermarking robust to many attacks from commercial 3D editing tools while a watermark embedded by interpolator watermarking fragile to the same attacks.     

Open source software licenses: Strong-copyleft, non-copyleft, or somewhere in between?

Studies on open source software (OSS) have shown that the license under which an OSS is released has an impact on the success or failure of the software. In this paper, we model the relationship between an OSS developer's utility, the effort that goes into developing an OSS, his attitude towards the freedom to choose an OSS license, and the choice of OSS license. We find that the larger the effort to develop OSS, the more is the likelihood that the OSS license would be free from restrictions. Interestingly, the result holds even when all OSS developers prefer restrictive licenses or less-restrictive license. The results suggest that least-restrictive or non-copyleft license will dominate other types of OSS license when a large effort is required to develop derivative software. On the other hand, most-restrictive or strong-copyleft licenses will be the dominant license when minimal effort is required to develop the original OSS and the derivative software.     

An SVD audio watermarking approach using chaotic encrypted images

This paper presents a new approach for audio watermarking using the Singular Value Decomposition (SVD) mathematical technique. The proposed approach can be used for data hiding in the audio signals transmitted over wireless networks and for multi-level security systems as will be stated in the applications section. This approach is based on embedding a chaotic encrypted watermark in the singular values of the audio signal after transforming it into a 2-D format. The selection of the chaotic encryption algorithm for watermark encryption is attributed to its permutation nature, which resists noise, filtering, and compression attacks. After watermark embedding, the audio signal is transformed again into a 1-D format. The transformation between the 1-D and 2-D formats is performed in the well-known lexicographic ordering method used in image processing. The proposed approach can be implemented on the audio signal as a whole or on a segment-by-segment basis. The segment-by-segment implementation allows embedding the same watermark several times in the audio signal, which enhances the detectability of the watermark in the presence of severe attacks. Experimental results show that the proposed audio watermarking approach maintains the high quality of the audio signal and that the watermark extraction and decryption are possible even in the presence of attacks.     

Robust lossless image watermarking based on α-trimmed mean algorithm and support vector machine

This paper presents a robust lossless watermarking technique, based on α-trimmed mean algorithm and support vector machine (SVM), for image authentication. SVM is trained to memorize relationship between the watermark and the image-dependent watermark other than embedding watermark into the host image. While needing to authenticate the ownership of the image, the trained SVM is used to recover the watermark and then the recovered watermark is compared with the original watermark to determine the ownership. Meanwhile, the robustness can be enhanced using α-trimmed mean operator against attacks. Experimental results demonstrate that the technique not only possesses the robustness to resist on image-manipulation attacks under consideration but also, in average, is superior to other existing methods being considered in the paper.     

A robust digital watermarking scheme for video copyright protection in the wavelet domain

This paper proposes a novel digital watermarking method for video based on a multi-resolution wavelet decomposition. The watermark used is a binary image. This watermark is embedded in the wavelet coefficients of the LH, HL and HH sub-bands of the second wavelet decomposition level by quantization. Every bit of the watermark is spread over a number of wavelet coefficients with the use of a key. The resulting watermarking scheme can be used for public watermarking applications, where the original image is not available for watermark extraction. We have tested the resilience of the watermarking algorithm against a series nine different attacks for different videos and improved the decoding BER by redundant embedding of the same watermark in different frames and by using an error correction code. Experimental results show that the embedded watermark is invisible and robust to attacks.     

基于安全容器的版权保护系统的客户端安全机制研究

提出了客户端信息产品的安全机制及实现。该机制使得消费者严格按照其登记的使用规则来使用信息产品，既保证了信息的偶然性丢失又确保了信息免遭故意攻击，从而有效地避免了侵权行为。