一种基于JPEG 2000的数字图像内容认证算法*

针对JPEG 2000图像内容认证的需求,提出一种适用于JPEG 2000图像认证的半脆弱水印算法.首先,将原始图像分块按Hilbert扫描顺序排列;然后在原图像分块Hilbert序列中选取分块,再结合各分块临界噪声阈值矩阵JND阈值,完成小波域的水印自适应嵌入;最后,引入私钥对水印进行加密,提高系统的安全性.在认证端,从接收到的图像提取其中所隐藏信息,比较接收到的图像和隐藏信息,判断内容发生变化的位置.实验表明,该算法对窜改等破坏图像内容的恶意操作有精确的检测和定位能力.

Digital Image Content Protection Algorithm Based on JPEG 2000

Based on the requirements of JPEG 2000 image authentication,a semi-fragile watermarking algorithm for JPEG 2000 image authentication was proposed.First,the original image was divided into blocks,which were rearranged into 1-D Hilbert sequence in Hilbert scanning order.Combined with JND,watermark adaptive embedding in wavelet domain was achieved.Finally,the secret key was introduced to ensure the security of the system.In the authentication side,the hidden information was extracted out from the received image,and rearranged inversely.If the received image is similar to the extracted information,the received image is credible,else that is to say,there exists a local region that is dissimilarity,i.e.the region is tampered,according to corresponding region of extracted information,the tampered position is repaired.Experimental results show the tampered areas are detected and located precisely.