基于喷泉码及CDMA扩频的数字水印盲算法  

Blind Digital Watermarking Algorithm Based on Fountain Code and CDMA Spread Spectrum

作　　者：张卫党[1] 吴琳 

机构地区：[1]郑州大学信息工程学院,河南郑州450001

出　　处：《郑州大学学报（工学版）》2017年第6期23-28,共6页Journal of Zhengzhou University（Engineering Science）

基　　金：国家自然科学基金资助项目(U1204607)

摘　　要：为了提高数字图像水印系统的鲁棒性和水印容量,提出一种基于喷泉码及CDMA扩频的数字图像水印算法.该算法首先对原始水印信息进行LT码预编码和CDMA扩频处理,然后将编码后的水印信息嵌入到载体图像的离散余弦变换DCT(Diserete Cosine Transform)域;在水印检测时,利用正交扩频码的互相关特性实现水印的盲检测,并且设定判决阈值将出错的水印比特删除,利用正确的水印比特进行LT码译码,提高了水印的鲁棒性.实验结果表明,该算法既能够保证水印系统具有良好的不可见性,又具有较大的水印容量,且对常见的水印攻击有较好的鲁棒性,尤其对JPEG压缩、噪声和剪切攻击有很强的鲁棒性.In order to improve the robustness and watermark capacity of digital image watermarking system, this paper presented a digital image watermarking algorithm based on fountain code and CDMA spread spec -trum techniques.LT code for the purpose of encoding the original watermark was adopted, and then CDMA spread spectrum techniques was used to generate the encoded watermark information.The encoded watermark information was embedded in the DCT domain of the carrier image.Blind recovery of the embedded data was achieved by using the character of cross-correlation function of the orthogonal spread spectrum code.The error watermark bits would be deleted by setting decision threshold and then using the correct watermark bits to de -code,which could ipmove the robustness of digital watermarking system.The result showed the scheme pro-posed in this paper could embed larger quantities of information and raise robustness,especially it was robust against JPEG compression,noise and cropping attacks.

关 键 词：数字水印 CDMA 喷泉码 DCT 鲁棒性 

分 类 号：TU528.1[建筑科学—建筑技术科学]