基于DWT-DCT的遥感影像数字水印方案

Watermarking Scheme for Remote Sensing Image Based on DWT and DCT

提出一种基于DCT和DWT的遥感影像数字水印方案。首先对水印图像进行Arnold置乱预处理,以破坏像素之间的空间相关性,增强算法鲁棒性;鉴于小波变换良好的局部性和时频分析特性以及多分辨率分析特性,而离散余弦变换具有较好的聚能效应,算法将载体遥感影像进行DWT变换,并选取其子带图像HL_1进行DCT变换;最后自适应的将数字水印嵌入所选子块的DC系数上。实验证明本文算法有效提高了水印的不可见性,对JEPG压缩、滤波和叠加噪声等攻击具有较好的鲁棒性。

A meaningful digital watermarking scheme for remote sensing image is proposed based on DCT and DWT. Firstly, the watermark image is scrambled by Arnold transformation to eliminate pixels＇ spatial correlation and enhance the robustness. As wavelet transformation has characteristics of well-localized, time-freqnency analysis and multi-resolution analysis, discrete cosine transformation has better shaped effect. Then DWT is applied to the host remote sensing image to get its subband HL1 . And I）CT is applied to the selected subband. At last the watermark is embedded adaptively into the DC coefficients of the selected subband. Experiments have shown that the algorithm proposed has good invisibility, with well robust against JEPG compression, filtering and noise superimposed attacking.