摘要
提出了一种新的基于 DCT的鲁棒公开水印算法 .算法首先将原图像各 8× 8DCT块按 Hilbert扫描顺序排列 ,然后每次伪随机选取两个在 Hilbert块索引序列中相邻的 8× 8块 ,通过调整两相邻块中对应低频系数间的大小关系 ,以嵌入水印信号 ,算法充分考虑了人类视觉系统屏蔽特性 ,嵌入水印与原图像是自适应的 .实验结果表明 ,该算法能较好地保证水印的不可见性 ,同时对常见的信号处理操作和剪切、旋转与缩放等几何扭曲是鲁棒的 ,特别是对锐化、对比度增强、边缘增强和直方图均衡等信号增强处理和
In this paper, a new robust public watermarking in DCT domain is proposed. First, the 8×8 DCT blocks of the host image are rearranged into a 1 D Hilbert sequence by using Hilbert curve, then two neighboring blocks in Hilbert sequence is pseudo randomly selected by using chaotic sequences. A watermark is embedded into the original image by modifying the polarity of the corresponding low frequency coefficients in the two neighboring blocks, and the watermark is adapted to the image by employing the masking characteristics of the human visual system, thus ensure that the watermark is invisible to human eyes. The experimental results show that the algorithm proposed in the paper is effective and robust to common signal processing operations and some geometric distortions, such as cropping, scaling and rotation. Especially, it receives high robustness under JPEG lossy compression and signal enhancement operations , such as sharpening, contrast enhancement, edge enhancement, histogram equalization, and so on.
出处
《小型微型计算机系统》
CSCD
北大核心
2004年第5期891-895,共5页
Journal of Chinese Computer Systems
基金
湖南省教育厅科研项目基金 ( 0 2 C183 )资助
