计算机工程
計算機工程
계산궤공정
COMPUTER ENGINEERING
2014年
9期
138-142
,共5页
特征点%三维网格%数字水印%仿射不变性%鲁棒性%透明性
特徵點%三維網格%數字水印%倣射不變性%魯棒性%透明性
특정점%삼유망격%수자수인%방사불변성%로봉성%투명성
feature point%three-dimensional grid%digital watermarking%affine invariance%robustness%transparency
针对三维网格水印空域算法无法兼顾嵌入量与透明性，且水印盲检测过程繁琐的问题，提出一种基于特征点的盲水印算法。选取三维模型最远两点为全局特征点建立全局坐标系，根据仿射不变性原理将原始载体仿射到一个固定的球型空间，以增强对多种几何攻击的抵抗能力。根据载体点密集程度将其等分成若干个局部空间，以局部空间中离质心最远点为局部特征顶点建立局部几何坐标系，从而增强算法的透明性。利用顶点在坐标系的投影角度来存储水印索引，实现盲水印。实验结果表明，该算法能有效抵抗旋转、缩放、噪声等攻击，具有强鲁棒性和较好的不可感知性，同时兼具盲水印检测优势。
針對三維網格水印空域算法無法兼顧嵌入量與透明性，且水印盲檢測過程繁瑣的問題，提齣一種基于特徵點的盲水印算法。選取三維模型最遠兩點為全跼特徵點建立全跼坐標繫，根據倣射不變性原理將原始載體倣射到一箇固定的毬型空間，以增彊對多種幾何攻擊的牴抗能力。根據載體點密集程度將其等分成若榦箇跼部空間，以跼部空間中離質心最遠點為跼部特徵頂點建立跼部幾何坐標繫，從而增彊算法的透明性。利用頂點在坐標繫的投影角度來存儲水印索引，實現盲水印。實驗結果錶明，該算法能有效牴抗鏇轉、縮放、譟聲等攻擊，具有彊魯棒性和較好的不可感知性，同時兼具盲水印檢測優勢。
침대삼유망격수인공역산법무법겸고감입량여투명성，차수인맹검측과정번쇄적문제，제출일충기우특정점적맹수인산법。선취삼유모형최원량점위전국특정점건립전국좌표계，근거방사불변성원리장원시재체방사도일개고정적구형공간，이증강대다충궤하공격적저항능력。근거재체점밀집정도장기등분성약간개국부공간，이국부공간중리질심최원점위국부특정정점건립국부궤하좌표계，종이증강산법적투명성。이용정점재좌표계적투영각도래존저수인색인，실현맹수인。실험결과표명，해산법능유효저항선전、축방、조성등공격，구유강로봉성화교호적불가감지성，동시겸구맹수인검측우세。
The general three-dimensional grid watermarking algorithm can not take into account the embedding capacity and transparency,and watermark blind detection is not easy to achieve. Aiming at these problems,this paper presents a blind watermarking algorithm based on feature points. It uses a global three-dimensional model to find the farthest points of global feature points. According to the affine invariance principle,the original carrier is affined to a fixed dome space of the global coordinate system to enhance the robustness. According to the point-intensive,it divides the carrier into some local space. In order to enhance the transparency of the algorithm,it makes the farthest point from the centroid in the local space as the local feature vertexes to establish local geometric coordinates. It achieves blind watermark by using the projection of the vertex angle defined in the coordinate system to store the watermark indexes. Experimental result shows that the proposed algorithm not only has good robustness and imperceptibility to such as geometric transformation, simplification, random noise and shear attacks,but also has blind watermark detection advantage.
