中文摘要：

为了对二维工程图内容的完整性进行认证,提出一种基于最优二叉查找树的零水印算法.首先对二维工程图中各个实体的拓扑结构进行编码,再与实体的句柄值相结合,进行小波分解后利用细节系数构造零水印.试验与分析表明该算法对不改变二维工程图内容的整体缩放、旋转、平移等操作具有较好的鲁棒性,对改变二维工程图内容的操作,如局部平移、实体删除、实体添加等恶意操作极度敏感,同时该算法还能够对二维工程图内容的篡改具有一定的定位能力.

英文摘要：

in order to authenticate the integrity of 2D engineer graphics,a zero-watermarking based on optimal binary searching-tree is proposed in this paper.Firstly,the topology of all entities in the 2D engineering graphic is encoded,then the wavelet decomposition is done to the handle values of the coded entities,and the zero-watermarking is constructed by the detail coefficients.Experimental results and analysis show that the proposed algorithm is robust against operations such as overall translation,rotation and scaling,which don′t change the content of the two-dimensional engineering graphics,but is sensitive to some malicious operations such as local translation,entity deletion,entity addition,and etc.Moreover,it is also able to locate the tampering area to a certain degree.