基于Turbo码的图像数字水印技术

在详细分析数字水印系统等效信道的基础上，提出了一种基于Turbo码的图像数字水印算法．该算法利用Turbo码的纠错性能和人眼视觉特性，以实现静止图像中数字水印的嵌入和提取；在水印嵌入之前，对水印序列进行Turbo码编码，然后利用人眼视觉特性进行水印嵌入，并采用了Turbo迭代译码算法进行水印提取，最后进行了数值仿真和算法比较．实验结果表明，该算法降低了水印在传输过程中的误码率，提高了水印的抗攻击能力，同时较好地解决了水印的鲁棒性和不可见性之间的矛盾．

An Application of Turbo Code in Image Watermarking

Based on the analysis of the equivalent channel in the digital watermarking system,a watermarking algorithm for digital image on the basis of Turbo code is proposed in this paper.The algorithm embeds and retrieves the watermark signature into and out of the static image by employing the Turbo code technology and the human visual characteristics.The watermark was first Turbo coded and embedded into the host image,then retrieved from the watermarked image using Turbo iterative methods.The results demonstrate that the proposed algorithm has geratly decreased the error code rate of the retrieved watermark and improved the attack-defending ability.