提出一种安全的抗JPEG压缩半脆弱自恢复水印算法.该算法能有效区分JPEG压缩与恶意篡改操作,并能根据检测结果恢复篡改区域.首先.图像划分为8×8图像块,然后进行DCT变换,并量化编码为12位水印信息,然后生成的水印位根据随机位置序列嵌入到对应图像块的中频系数中.实验结果证明,提出的算法能有效定位篡改区域,并进行恢复,同时能抵抗JPEG压缩.
In this paper, a semi-fragile waterinarking scheme with selLrecovery is proposed. The proposed scheme can distinguish malicious tamper from JPEG compression,and can recover the tampered region based on tamper detec- tion result. Firstly, the image is divided into 8 X 8 image blocks; DCT is performed on them, and then quantize the DCT coefficients using the per-determined quality factor. The authentication watermark bits are generated from DCT coefficients and embedded into the DCT domain of the im- age. Experiment results demonstrate that the proposed algo- rithm not only has capability of superior localization and self- recovery, but also tolerate JPEG compression while keeping sensitive to malicious manipulations.