面向电子航海图特征点角度构造的零水印算法  

A zero-watermarking algorithm for Electric Navigational Chart feature points angle construction

作　　者：陈阳 彭认灿[1,3] 董箭 陈轶[4] 李彬彬 CHEN Yang;PENG Rencan;DONG Jian;CHEN Yi;LI Binbin(Department of Military Oceanography and Hydrography&Cartography,Dalian Naval Academy,Dalian,Liaoning 116018,China;Chart Information Center,Tianjin 300450,China;Key Laboratory of Hydrography and Cartography of PLA,Liaoning 116018,China;Naval Research Academy,Beijing 100073,China)

机构地区：[1]海军大连舰艇学院军事海洋与测绘系,辽宁大连116018 [2]海图信息中心,天津300450 [3]海洋测绘工程军队重点实验室,辽宁大连116018 [4]海军研究院,北京100073

出　　处：《测绘科学》2021年第11期141-146,共6页Science of Surveying and Mapping

基　　金：国家重点研发计划项目(2017YFC1405505)。

摘　　要：针对电子航海图(ENC)在应用过程中适用于版权保护的数字水印研究较少的现状,提出一种基于电子航海图特征点和角度的零水印算法。采用道格拉斯普克(D-P)算法提取电子航海图要素中的特征点;设计一种基于参考点同心圆的均匀分组方法,并通过对特征点点位坐标作相应的预处理,即将以经纬度表示的点位坐标转化为极坐标表示;在每个分组内按照设定的次序比较相邻特征点之间的角度,将大于等于角度均值的记为1、否则记为0,从而得到每组的特征序列;将该特征序列与Arnold置乱加密后的QR码水印图像进行异或操作,构造得到电子航海图零水印图像。由于该算法既可保证电子航海图要素的完整性,又不对其数据作任何修改,能很好解决传统水印算法中存在的不可感知性与鲁棒性之间的矛盾。实验结果表明,该水印算法对常见的几何攻击、增删点和裁剪等数据编辑具有很好的鲁棒性,同时,抗精度约减能力较好。In view of the lack of research on digital watermarking for copyright protection in the application of ENC,a zero-watermarking algorithm based on feature points and angles of ENC is proposed.Firstly,the D-P algorithm is used to extract the feature points from the elements of ENC;Secondly,a uniform grouping method based on the concentric circles of reference points is designed,and the coordinates of feature points are preprocessed,that is,the coordinates expressed in latitude and longitude are transformed into polar coordinates;Then,the angles between adjacent feature points are compared according to the set order in each group,if the angle greater than or equal to the average angle,the record is 1,otherwise 0,so as to obtain the feature sequence of each group;Finally,the XOR operation is done between the shuffled QR code watermark image and characteristic value,then the ENC zero watermark image is obtained.Because the algorithm can not only ensure the integrity of ENC elements,but also do not make any changes to its data,it can solve the contradiction between imperceptibility and robustness in traditional watermarking algorithms.Experiments show that the algorithm has good robustness against common geometric attacks,adding and deleting points and clipping data,and has good anti precision reduction ability.

关 键 词：电子航海图 特征点 角度 零水印 置乱 QR码 

分 类 号：P229[天文地球—大地测量学与测量工程]