基于新闻文本图像的鲁棒水印算法  

Robust watermarking algorithm based on news text image

作　　者：刘尧 杜庆治[1] 马迪南 龙华[1,3] 邵玉斌 黄喜阳[1] LIU Yao;DU Qingzhi;MA Dinan;LONG Hua;SHAO Yubin;HUANG Xiyang(Faculty of Information Engineering and Automation,Kunming University of Science and Technology,Kunming 650500,China;Yunnan Daily Press Group,Kunming 650032,China;Yunnan Provincial Key Laboratory of Media Integration,Kunming 650228,China)

机构地区：[1]昆明理工大学信息工程与自动化学院,云南昆明650500 [2]云南日报报业集团,云南昆明650032 [3]云南省媒体融合重点实验室,云南昆明650228

出　　处：《现代电子技术》2024年第3期43-50,共8页Modern Electronics Technique

基　　金：云南省媒体融合重点实验室开放项目(320225403)。

摘　　要：在新闻文本图像中,现有的水印算法没有将表达文本部分的区域与其他背景区域进行区分,并且对二值水印图像嵌入时只在单通道嵌入导致鲁棒性不高。针对以上问题,提出基于新闻文本图像的鲁棒水印算法。首先将新闻文本图像进行大津阈值分割(OSTU),将文本与背景区域区分开,选择文本区域进行嵌入加深对重要信息的版权保护;接着将文本图像Cr和Cb通道的文本区域进行离散小波变换(DWT)后,利用主成分分析(PCA)进行能量集中并计算各主成分贡献率,通过比较贡献率来选择嵌入的主成分;最后对主成分及水印图像进行奇异值分解(SVD)完成水印嵌入。经过实验表明,嵌入水印图像在面对滤波等大多数常规攻击的NC值都在0.99以上,表明该算法有较强的鲁棒性,同时该算法在嵌入水印后图像的PSNR均值为45.66 dB,保证了不可感知性。In news text images,the existing watermarking algorithms fail to distinguish the regions of expressing text from the other background regions.In addition,they only embed binary watermark images in a single channel,which results in low robustness.In view of this,a robust watermarking algorithm based on news text image is proposed.The news text image is segmented by Otsu threshold segmentation(OSTU)to distinguish the text from the background regions,and the text region is selected for embedding to deepen the copyright protection of important information.The text regions of the Cr and Cb channels of the text image are subjected to discrete wavelet transform(DWT),and principal component analysis(PCA)is used to concentrate energy and calculate the contribution rates of each principal component.The embedded principal components are selected by comparing the contribution rates.The singular value decomposition(SVD)is performed on the principal component and watermark image to complete watermark embedding.After experiments,the NC value of the embedded watermark image in the face of most conventional attacks such as filtering is above 0.99,which indicates that the algorithm has strong robustness.At the same time,the average PSNR of the image after embedding the watermark is 45.66 dB,which ensures imperceptibility.

关 键 词：图像水印 大津阈值分割 主成分分析 小波变换 奇异值分解 NC值 

分 类 号：TN911.73-34[电子电信—通信与信息系统] TP309.7[电子电信—信息与通信工程]