摘要
在空域内嵌入水印,具有速度快、容易实现等优点,但如何提高其安全性和抗剪切能力是急待解决的难点。该文提出一种基于混沌映射的鲁棒水印算法能够解决这个问题。首先,运用二值混沌序列对水印信息加密,再用混沌映射对载体图像进行混沌置乱变换;其次,将加密水印嵌入到变换图像位平面的第4、5、6位;最后,反变换得到嵌入了水印的图像。实验表明,该算法具有较好的透明性和抗剪切能力,即使在受到剪切3/4的强攻击时仍然能提取出较清晰的水印信号。
Watermarking over the spatial domain has advantages of high speed and easy realization, but there is a difficult problem that is how to improve the security and capability to against scrapping. A robust watermarking algorithm based on chaotic map is presented. First, the original binary watermark is masked by a binary chaotic sequence and the original image is permuted according to a chaotic map. Then, the masked watermark is used to modify the 4th, 5th, or 6th bit of the corresponding pixels in the permuted image. Finally, the permuted and watermarked image is inverse-permuted and the result is obtained. The Matlab simulation results have demonstrated that the scheme has a good transparence and resistance to be cropped .The extracted watermarks are still readily recognizable even if cropped by 75%.
出处
《计算机工程》
CAS
CSCD
北大核心
2005年第9期34-36,共3页
Computer Engineering
基金
国家自然科学基金资助项目(60271019)
教育部博士基金资助项目(20020611007)
关键词
数字水印
混沌映射
图像置乱
Digital watermarking
Chaotic map
Image permuting
