基于喷泉码和人眼视觉系统的扩频数字水印方案

为了更好地在Contourlet域里选择合适的嵌入位置和嵌入强度，提出基于人眼视觉系统（HVS）的视觉掩蔽.利用此视觉掩蔽在Contourlet域里选择适当的嵌入位置和嵌入强度来嵌入水印信息，提高水印的保真度；采用喷泉码编码对水印图像进行预处理加密，增加水印的安全性；利用扩频水印技术增强水印方案抵抗常见水印攻击的能力，提高水印方案的鲁棒性.Matlab仿真结果表明，新水印设计方案具有较高的鲁棒性和安全性，保真度得到较大幅度的提高.

Spread Spectrum Digital Watermarking Scheme Based on Fountain Code and Human Vision System in Contourlet Domain

In order to better select the suitable embedding position and embedding strength in the Contourlet domain，the visual masking based on the Human Visual System（HVS）for Contourlet Transform is proposed.We use this visual masking in the Contourlet domain to select the appropriate embedding strength and embedding position and embed the watermark information，thus improving the invisibility of watermarking scheme.The watermark image is pre-processed by using the fountain code to be encoded，which increases the security and the decoding rate.We use spread spectrum watermarking technology to enhance the ability of watermarking scheme to resist common watermark attacks,which improves the robustness of the watermarking scheme.Experimental results show that the proposed scheme has higher invisibility and robustness compared with the common watermarking scheme，and the security is also improved.