一种数字水印算法及其复杂度分析  

SPLINE-BASED DIGITAL WATERMARKING ALGORITHM AND ITS COMPLEXITY

作　　者：姚志强[1] 潘日红[1] 陈荔聪[1] 林崧[1] 

机构地区：[1]福建师范大学计算机科学系,福州350007

出　　处：《数值计算与计算机应用》2005年第4期241-248,共8页Journal on Numerical Methods and Computer Applications

基　　金：福建省自然科学基金项目(A0510012;A0210016)福建省教育厅基金项目(JA03028)资助课题.

摘　　要：稳健性是稳健水印算法的主要目标,为改善水印稳健性,图像水印算法中可先用样条方法 为图像建模,再实现水印嵌入操作,比如由低频子图像各行小波系数构成的控制多边形定义 一簇B样条曲线,适度改变B样条曲线并反算其控制顶点以得到水印图像．本文探讨了这 个算法,进而重点分析了反算控制顶点的算法及其时间复杂度．Robustness is the aim of digital watermark. To improve the robustness of watermarks, some algorithms are proposed to apply spline and model-building in watermarking, including this one described in this paper： In the beginning a discrete wavelet transformation is made to an image and a group of uniform Bspline curves are defined with the low resolution wavelet coefficients as control points. Afterwards the watermarked image can be derived by disturbing some points of the curves and calculating new control points backwardly. Conclusively the paper explores the backward calculating algorithm of new control points and addresses its time complexity.

关 键 词：数字水印 控制顶点 B样条曲线 算法复杂度 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]