摘要
针对现有数字水印算法对于几何攻击稳健性差、嵌入彩色版权图像信息量过多导致效率低下等问题,提出一种基于SURF(speed up robust features)几何校正和半色调映射加密的彩色零水印算法。基于SURF提取载体图像的特征点,并将其特征点信息保存为密钥用于实现盲检测。在版权验证过程中,提取受攻击图像的特征点并进行密钥匹配,使用筛选后的特征点估计出仿射矩阵,对受攻击的图像进行几何校正。同时,根据半色调原理对版权标识进行预处理,使用像素扩展的三通道二值矩阵表示彩色图像,并根据加密规则对水印图像进行半色调子块映射加密,在减少嵌入信息量的同时保留了彩色版权图像的颜色和结构信息,增加了水印信息的安全性。实验结果表明,提出的零水印算法在面对几何攻击和非几何攻击时都具有很强的稳健性,生成的零水印信息更安全。
A color zero-watermarking algorithm based on speeded-up robust features(SURF)to correct geometric distortions and halftone mapping encryption is proposed to address problems associated with poor robustness against geometric attacks in existing digital watermarking algorithms and low efficiency due to excessive embedded color copyright image information.First,the feature points of the carrier image based on SURF algorithm were extracted and feature point information was saved as a key for blind detection.In the copyright verification process,after the feature points of the attacked image were extracted and keys were matched,the geometric correction of the attacked image was implemented based on affine matrix estimated by filtered feature points.Simultaneously,the copyright identification was preprocessed according to the halftone principle.The color image was represented by a threechannel binary matrix with pixel expansion,and the watermark image was encrypted by halftone sub-block mapping according to the encryption rules.In proposed algorithm,the color and structure information of the copyright images were retained while the amount of embedded information was reduced,and the security of the watermark information was increased.The experimental results demonstrate that the proposed zero-watermark algorithm is robust against geometric and nongeometric attacks and the generated zero-watermark information is more secure.
作者
胡森
吴德阳
仲美玉
王苗苗
赵静
唐勇
曲长波
Hu Sen;Wu Deyang;Zhong Meiyu;Wang Miaomiao;Zhao Jing;Tang Yong;Qu Changbo(College of Software,Liaoning Technical University,Huludao,Liaoning,125105,China;College of Information Science and Engineering,Yanshan University,Qinhuangdao,Hebei,066004,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2021年第20期220-234,共15页
Laser & Optoelectronics Progress
基金
国家自然科学基金(61902340)
河北省自然科学基金(F2018203060)
秦皇岛市科学技术研究与发展计划项目(201602A018)。
关键词
图像处理
彩色零水印
半色调映射加密
SURF
imaging processing
color zero-watermarking
halftone mapping encryption
speed up robust features
