数字图像成像渠道取证是数字图像取证的一个重要研究内容。已有研究成果主要集中在取证方法的构建方面，大多通过从图像空间域或变换域抽取特征，利用模式分类的方式实现取证。但在取证机理上尚未形成系统的研究，在取证特征的选取方面缺乏有效的指导准则，导致取证结果缺乏科学合理的解释，取证算法的性能提升困难，影响了取证方法的推广应用。针对当前研究存在的突出问题，本项目深入研究数字图像成像渠道取证的非线性机理及其应用的关键技术，主要包括：成像渠道的非线性因素分析与定量表达方法、成像渠道取证的非线性机理、SVM分类器的非线性优化方法、非线性因素在图像成像渠道取证中的应用方法。通过研究，解决数字图像成像渠道取证特征的有效获取与表达问题，完善数字图像成像渠道取证的有关理论，并拓展非线性理论的应用领域。研究成果可应用到犯罪调查、新闻报道、情报分析等领域，为维护社会稳定和促进社会发展发挥重要的作用。

Digital image acquisition pipeline forensics is an important research topic in digital image forensics. The current works are mainly concentrated on the construction of forensics methods. Most of them extract features from image space domain or transform domain, and then accomplish forensics by using pattern classification. However, few works has been done to the research of forensics mechanism, and principles for the selection of forensics features are not established. Thus, the forensics results lack of scientific and reasonable explanation, and the performance of the forensics method is hard to be improved, which limits its popularization and application. Aiming at the prominent problems existed in the current research of digital image acquisition pipeline forensics, this proposal makes deep researches on the key technologies for the nonlinear mechanism of digital image acquisition pipeline forensics and its applications, including: analysis and expression methods for nonlinear factors in image acquisition pipeline, nonlinear mechanism of digital image acquisition pipeline forensics, nonlinear optimization method for SVM classifier, and the application of the nonlinear factors in image acquisition pipeline forensics. Through this research, resolve the problems of effective acquisition and expression of forensics features for digital image acquisition pipeline forensics, compliment the related theory for digital image acquisition pipeline forensics and extend the application field of nonlinear theory. The research achievements can be applied for criminal investigation, news report, intelligent analysis and etc. It will play an important role in protecting the social stability and promoting the social development.