基于视觉密码学的moiré纹度量和构建研究

In visual cryptography scheme (or visual secret sharing scheme, abbreviated as VCS), the secret image can be recovered by overlaying and aligning some shares on an overhead projector, while moiré patterns can be seen by the direct superposition of two(or more) layers in moiré phenomenon. The property of the reconstruction of VCS is the same as that of moiré phenomenon. The difference between VCS and moiré phenomenon is that the quality of the recovered secret image can be measured in VCS, while the quality of moiré patterns in moiré theory cannot. The model of relationships, which describes moiré patterns and their factors, cannot be obtained in moiré theory. This project aims to measure moiré patterns using VCS, human visual system, optimization theory, probability and statistics's knowledge on a single moiré pattern and adjacent moiré patterns, and give the relationship model between the construction of typical moiré patterns and its influencing factors. On this basis, combined with the production technology of typical moiré patterns and extended VCS, we will propose some algorithms for specified layer generated to obtain specified moiré patterns; and the results obtained will be applied to the field of image encryption, information hiding and anti-counterfeiting technology etc.

在视觉密码学(visual cryptography scheme,简写 VCS )中，若直接对着光线叠加一定的分存片，就可以看见秘密图像，这一性质与moiré现象中直接叠加两个（或多个）图层可以清晰的看见moiré纹的重构方式是相同的，不同之处是VCS中重构质量有量化值，而moiré理论中对moiré纹质量的客观度量没有涉及，如何刻画moiré纹与产生它的影响因素之间的关系模型，是该领域中尚未解决的难题。本项目拟采用VCS、人类视觉系统、优化理论和概率统计等知识对单个moiré纹和相邻moiré纹的变化给出相应的客观度量，并以此来构建典型moiré纹与产生它的影响因素之间的关系模型。在此基础上，结合典型moiré纹的生成技术和扩展的VCS，拟设计出指定图层产生指定moiré纹的构造方案，并将新的结果应用到图像加密、信息隐藏和防伪技术等领域中。

moiré纹现象中直接叠加两个（或多个）图层可以清晰的看见moiré纹的重构方式与视觉密码学是相同的，不同之处是VCS中重构质量有量化值，而moiré理论中对moiré纹质量的客观度量没有涉及，通过本课题的研究，给出了区域扩展的VCS，给出了VCS中随机性模型的刻画，给出了基于moiré纹的两种图形隐藏的加密思想，提出了用随机长度的随机线扰乱形变图层的算法；提出了基于moiré纹的图像加密中的参数的研究；将moiré纹的技术应用到图像加密，音视频水印、隐写技术、同态加密等相关领域并取得了一些有价值的研究结论。.经过几年基础研究和实际应用，项目组获2015年度教育部技术发明一等奖、获2015年电子学会技术发明一等奖以及在2017年获第22届全国发明展览会金奖，并授予国家新闻出版广电总局数字内容防伪与安全取证重点实验室。已发表论文37篇，其中SCI收录期刊13篇，EI收录期刊16篇。