【摘要】 随着计算机和网络技术的飞速发展,数字图像、音频和视频产品越来越需要一种有效的版权保护方法,所谓数字水印就是一种嵌入到图像、视频或音频数据中的不可见标志,可以用于多媒体数据的版权保护、认证和标注等。该文提出了一个有效的自适应育水印算法,在水印检测过程中不需要原始图像。原始图像经小波变换后,选择内嵌水印所需要的子带,水印根据邻居特征平均值法和奇偶判决法内嵌到频域中所选择的子带上。实验结论和攻击测试表明,该文所提议的算法能得到高逼真度的加水印图像,对如 JPEG有损压缩、中值滤波、附加噪声、伸缩、裁剪等各种图像处理的攻击有较强的稳健性。更多还原

【Abstract】 A digital watermark is an invisible mark embedded in digital images,video or audio documents,which may be used for a number of different purposes including copyright protection,authentication and captioning. In this paper, an effective adaptive watermarking algorithm for still images is proposed. This is a blind watermarking which can confirm the copyright without original image. The original image is transformed using wavelet transform and the watermark is embedded in selected subband of frequency domain according to neighboring symbol’s mean value and odd-even adjugement rule. Experimental results and attack analysis show that the watermark algorithm proposed in this paper can produce the watermarked image which has high fidelity and is robust against some image processing operations, such as JPEG lossy compression,median filtering, additive noise, scaling, and cropping attacks.更多还原