基于DWT和DCT数字图像鲁棒水印算法

基于离散小波变换和离散余弦变换,利用混沌系统的优良特性,提出一种新的变换域水印算法.水印嵌入时,首先将宿主图像进行小波变换后选取中频区域,再进行DCT变换,根据水印图像大小进行分块嵌入水印算法在保证不可见性的前提下,最大程度的保证了水印算法的鲁棒性.仿真实验表明,算法在多种攻击下表现出良好的鲁棒性,具有一定的实用意义.

Robust Digital Image Watermarking Algorithm Based on DWT and DCT

A new transforming domain watermarking algorithm is proposed based on discrete wavelet transformation （DWT） and discrete co- sine transformation （DCT）. Chaotic system is involved in the watermarking, which improves the security of the proposed algorithm further. Firstly, the host image is transformed into wavelet domain and the relative intermediate frequency regions are obtained, and then the embed- ding positions are transformed into cosine domain and partitioned into blocks according to the size of watermarking to be embedded. The algo- rithm ensures the robustness of watermarking furthest on the premise of ensuring the invisibility. The experimental evaluation demonstrates that the proposed algorithm could withstand a variety of attacks.