基于最低有效位的量子图像水印

利用最低有效位的思想，提出了一个量子图像水印方案。在该方案中，嵌入者通过置换载体图像灰度值的某一个比特把水印图像嵌入到量子载体图像的某些像素中，这些像素由一个私钥决定。只有拥有这个私钥的版权者才可以在不知道初始载体图像的前提下提取出水印信息。分别设计了嵌入和提取算法的量子电路图，并给出了该水印算法的计算机仿真。通过比较嵌入载体图像和初始载体图像之间的峰值信噪比，说明提出的水印方案实现了不可见性。实验结果也表明，提出的水印方案具有良好的可伸缩性。

A watermarking strategy for quantum image based on least significant bit

Drawing ideas from least significant bit, a quantum watermarking strategy was proposed. In this strategy, one embedder embeded a watermark image into some pixels of quantum carrier image by changing one bit of gray-scale value of carrier image, these pixels were determined by a private key. Only the copyright ower who held the private key could extract the watermark information without knowledge of the original carrier image. Quantum circuits of embedding and extracting algorithms were respectively designed. Moreover, the computer simulation of the proposed watermarking algorithm was given. By comparing the peak signal-to-noise ratio between the embedded carrier image and original carrier image, it indicates that the proposed watermark strategy achieves invisibility. The experimental results also show that the proposed watermark strategy is flexible.