基于分块压缩感知的图像半脆弱零水印算法

针对数字图像的内容认证和完整性保护问题,提出了一种基于分块压缩感知(Compressive sensing, CS)的图像 半脆弱零水印算法(Block compressive sensing based image semi-fragile zero-watermarking, BCS-SFZ).首先将图像划分成若干分块,分块大小可以根据水 印数据量和篡改定位精度调整.再按照压缩感知理论对各个图像块进行观测, 并将观测值作为零水印信息注册保存.实验结果表明, BCS-SFZ算法可以准确定位非法篡改并借助水印信息恢复被篡改的区域. 压缩感知理论的引入为算法提供了保密性支持,并且有利于实现图像成像与水印生成的同步,同时该算法实现简单,计算复杂度低.

Block Compressive Sensing Based Image Semi-fragile Zero-watermarking Algorithm

To aim at content authentication and integrity protection problems in digital image application, a block compressive sensing based image semi-fragile zero-watermarking (BCS-SFZ) algorithm is proposed. Firstly, the image is divided into several sub blocks. The block size can be adjusted according to the data quantity of watermark and tamper localization accuracy. Secondly, each image block is observed in accordance with the theory of compressive sensing. Finally, the measurements are registered and preserved as the zero-watermarking. The experimental results show that BCS-SFZ can accurately locate the illegal tampering and recover the tampered area with the watermark information. The introduction of compressive sensing theory provides secrecy guarantee for the algorithm, and is conducive to synchronization of imaging and generating watermark. Also, the algorithm is simple and has a low computational complexity.