基于喷泉码的数字图像水印的研究

Study of Digital Image Watermarking Based on Fountain Code

为了提高数字图像水印信息传输过程中的鲁棒性,这里提出一种基于喷泉码的数字水印算法,该方案利用喷泉码在删除信道中的优异性能,将信道编码与扩频水印结合后在图像中嵌入水印信息.然后对这种方案在水印系统中的鲁棒性进行了一系列仿真测试,并和未编码方案及水印系统中常用到的LDPC编码方案作了比较.仿真证明,应用该方案可以提高数字水印系统的鲁棒性,降低水印信息在传输过程中的误码率,而且水印编码复杂度要远远低于LDPC方案.

This paper presents a new algorithm based on fountain code to improve robustness of the watermark in digital image watermarking system. Employing the outstanding performance of LT codes in erasure channel, the proposed scheme combines channel coding with spread spectrum watermarking to recover watermark. In the end, this paper makes a series of tests with fountain coding scheme and LDPC coding scheme and non cod- ing scheme, the result shows the scheme proposed in this paper can raise robustness of the digital watermark- ing system, lower the bit error rate （BER） between watermark and recovered watermark effectively. In addi- tion, fountain coding scheme has lower complexity compared with LDPC coding scheme.