基于DCT变换的数字水印算法研究

An Algorithm to Digital Watermarking based on DCT

为提高图像数字水印的抗攻击能力,提出了一种基于DCT变换的数字水印算法。首先将水印信息转换成对应的QR码,然后通过Arnold置乱技术将QR码进行预处理,接着对载体图像实现8×8分块,对每个分块进行DCT变换,最后按一定的规律将预处理后的水印信息嵌入到各分块中,从而完成水印信息的嵌入。实验结果表明,此算法对噪声叠加、剪切等常见攻击具有较强的鲁棒性,能在保证水印隐藏性的同时抵抗住一定程度的攻击,满足标识图像版权信息的需求。

This paper presents an new digital watermarking algorithm based on DCT to improve the antiattack performance of image digital watermarking.Firstly,the watermarking has been transformed to QR cord.Then arnold transform technique has been used to preprocess the QR code.The carrier image has been divided into 8*8 blocks,and DCT transform has been performed to every block.Finally,the preprocessed watermarking information has been embedded in every block according to a certain rule to finish the process of watermarking information embedded.The experimental results show that the algorithm in this paper has strong robustness against noise superposition,cutting,and other common assaults.This algorithm can resist a certain degree of attack while hiding watermark,which meets the needs of identification of image copyright information.