基于压缩感知的鲁棒可分离的密文域水印算法

为了满足密文域水印嵌入的需要，该文基于压缩感知技术，提出一种鲁棒可分离的密文域水印算法。首先，内容拥有者将图像进行不重叠分块，利用边缘检测手段划分重要块和非重要块。重要块用传统加密方式进行加密，非重要块用压缩感知技术进行加密，同时为水印嵌入留出一定空间，然后根据嵌入密钥，实现二值水印的密文嵌入。在接收端获取图像内容和水印的方式是可分离的，同时根据含水印的密文图像块的像素分布特性可重新判断块的属性，避免了传输块属性信息。此外，水印信息重复4次嵌入在密文图像的不同区域，保证了水印的鲁棒性。实验结果显示所提方案在抵抗适度攻击时具有鲁棒性和安全性。

Robust and Separable Watermarking Algorithm in Encrypted Image Based on Compressive Sensing

To meet the watermarking requirement in encrypted domain, a novel scheme for robust and separable watermarking in encrypted image is proposed based on Compressive Sensing (CS). Firstly, the content owner divides the original image into non-overlapping blocks, and then the edge-detection method is utilized to classify all blocks into significant or insignificant blocks. For the former, traditional method is used for encryption; and for the latter, CS is used for encryption, which leaves some space for embedding data. Then, the binary watermark is permutated with the data hiding key, and embedded into the encrypted image. The way to obtain the image content and watermark is separable, and the attributes of the block can be regained according to pixel distribution of the watermarked image, which avoids transmitting the attribute information. Furthermore, the watermark is embedded four times in the encrypted image, which guarantees its robustness. The experimental results show that the proposed scheme is robust and secure against moderate attacks.