基于局部概率密度不变特征的强鲁棒数字图像水印关键技术研究

.The rapid development of new information technologies has improved the ease of access to digital information. It also leads to the problem of illegal copying and redistribution of digital media. The concept of digital watermarking came up while trying to solve the problems related to the management of intellectual property of media. A digital image watermarking scheme must be robust against a variety of possible attacks. Attacks which attempt to destroy or invalidate watermarks can be classified into two types, noise-like common signal processing and desynchronization attacks. Desynchronization attacks are more difficult to tackle than other types of attacks. It is a challenging work to design a robust image watermarking scheme against desynchronization attacks..In recent years, several watermarking approaches that counterattack desynchronization attacks have been developed. These approaches can be roughly divided into Exhaustive search, Spread spectrum modulation, Invariant domain, Synchronization correction, and Feature-based algorithm. Through in-depth research and analysis, we observed that the former four image watermarking approaches are usually vulnerable to some desynchronization attacks, and the feature-based watermarking methods exhibit more promising than others in terms of robustness. However, there are some main drawbacks indwelled in current feature-based schemes: First, the adopted intensity based feature point detectors are sensitive to texture region, and the feature points are distributed unevenly. Secondly, the extracted local feature regions aren't fully affine invariant. Thirdly, the nonoverlapping feature region set is not selected according to local image content. Fourthly, the watermark is not embedded adaptively by considering fully the image features such as the brightness, edges, and region activities. These practical problems existed in the current feature-based watermarking restricts the robustness against desynchronization attacks and common image processing operations. .This project will study the theory and method of robust image watermarking, identify the key factors for the robustness of image watermarking, and build the local invariant feature based overall image watermarking system resilient to desynchronization attacks. The main contents include: Construct the multiscale probability density image feature point detector; Build the fully affine invariant local feature regions based on probability density Hessian matrix and Tsallis entropy; Give the derivation of fast calculation method of exponent invariant moments; Design the visual masking based adaptive watermark embedding scheme, and corresponding parallel image watermarking algorithm; Study the intelligent watermark agent technology and corresponding image watermarking software. The project will eventually build the local invariant probability density feature based image watermarking model, and develop the corresponding image watermarking software agents.

作为多媒体作品版权保护的有效手段，数字水印技术已成为国际学术界的研究热点。但是，现有绝大多数图像水印算法仅仅能够对抗常规的信号处理和部分简单的全局仿射变换，而无法有效抵抗一般性去同步攻击，即抗去同步攻击的图像水印算法研究仍然是一项富有挑战性的工作。本项目将采用概率密度建模技术，研究高度鲁棒的数字图像水印理论与方法，确定影响图像水印鲁棒性的关键因素，建立基于局部概率密度不变特征的可有效抵抗去同步攻击的强鲁棒数字图像水印整体系统。包括构造多尺度概率密度图像特征点检测器；建立基于概率密度Hessian矩阵与Tsallis熵的完全仿射不变局部特征区域；推导快速指数不变矩计算方法；设计基于视觉掩蔽的自适应图像水印方案及相应的并行化算法；研究智能图像水印代理技术和基于此技术的图像水印软件系统。本项目最终将建立起基于局部概率密度不变特征的数字图像水印模型，并研制出基于该模型的图像水印Agent软件包。

数字水印（Digital Watermarking）作为传统加密方法的有效补充手段，是一种可以在开放的网络环境下保护版权和认证来源及完整性的新技术，已引起了人们的高度重视，并已成为国际学术界研究的一个热点。近年来，用于版权保护的鲁棒图像水印技术研究取得了很大进展，并陆续提出了一系列优秀的鲁棒图像水印算法。但遗憾的是，现有大多数图像水印技术抵抗去同步攻击（特别是局部去同步攻击）的能力均较差。.鉴于此，本项目结合概率密度、尺度空间、人眼视觉感知等理论，研究了基于同步校正的抗全局几何变换数字图像水印算法，建立了基于局部概率密度不变特征的可有效抵抗局部去同步攻击的自适应数字图像水印系统，设计了可取得鲁棒性与不可感知性良好平衡的统计模型图像水印方案，初步解决了现有数字图像水印领域存在的无法有效抵去同步攻击的问题。.本项目已取得一系列高水平学术研究成果，包括（1）获国家发明专利8项。其中，授权3项；实审5项；（2）在《ACM T MULTIM COMPUT》、《INFORM SCIENCES》、《PATTERN RECOGN》、《Neural Networks》、《J SYST SOFTWARE》、《J VIS COMMUN IMAGE R》、《MULTIMED TOOLS APPL》、《计算机研究与发展》等国内外权威期刊发表学术论文22篇（其中，有21篇被SCI收录、1篇被EI收录）；（3）出版学术专著2部；（4）获辽宁省科技进步二等奖（2012）、辽宁省科技进步三等奖（2015）、辽宁省自然科学学术成果一等奖（2014）等多项；（5）所指导的研究生中，多人获得“辽宁省优秀学位论文”、“辽宁省优秀学位论文提名论文”称号；（6）项目负责人于2013年被中共大连市委、大连市人民政府评选为“大连市第二批突出贡献专家”。.本项目研究成果，有效解决了现有相关技术研究领域所存在的一系列疑难问题，进一步丰富和完善了国内外相关科学技术领域的新内容，并为相关科学技术的广泛应用提供了新途径。目前，相关研究成果已陆续被多家单位所采纳，并初步应用于电子商务/电子政务系统、数字作品的服务付费、印刷品防伪、多媒体数据的跟踪和检测等诸多领域。