摘要
随着信息时代的到来,数字水印不仅在版权保护、来源认证、私有探测领域受到了前所未有的重视,而且在信息安全领域也引起了广泛的关注。提出了一种基于B-rep的CAD模型盲水印算法,该算法主要针对NURBS曲线或曲面来嵌入水印,能精确地保持模型的形状。首先遍历模型找到所有的NURBS曲线,并将其依据曲线的长度进行排序,然后利用相邻节点插入法将生成的水印嵌入到排好序的NURBS曲线中,对半盲水印算法进行改进得到了盲水印算法,从而在提取水印时不需要原始模型和原始的水印消息,直接从相对应的NURBS曲线中进行水印提取,最后通过比较提取出来的水印和原始水印的相似度来验证水印是否被篡改。实验表明该算法能够在模型中嵌入大容量的水印消息,并减少了提取水印的时间。
With the appearance of informatization period,digital watermarking is attached importance to a great extent in these facts such as copyright protecting,source authentication,private detection and on,and becomes one hot research field of information security.This paper proposes a blind watermarking algorithm based on B-rep for CAD models,the algorithm embeds watermarking aiming at NURBS surfaces or curves,and its merit is preserving the model＇s shape exactly.Firstly,we go through the model for obtaining all NURBS primitives,and order these primitives by its length,then use interfacing knot insertion method to embed generated watermarking into ordered primitives.Semi-Blind watermarking is improved and becomes All-Blind watermarking,so we can directly extract watermarking from corresponding ordered NURBS curves,and don＇t need provide origin model and origin watermarking messages.At last,through comparing the similarity both the extracted watermarking and origin messages to test if this watermarking is distorted or not.Results show blind algorithm can embed high-capacity watermarking into models,and reduce the time of extracting watermarking.
出处
《计算机系统应用》
2011年第3期54-59,共6页
Computer Systems & Applications
基金
国家高技术研究发展计划(863)(2007AA04Z1A5)
