一个基于DWT和DCT的盲的数字图象水印技术

数字水印是解决信息安全和版权保护的有效的方法，已成为多媒体信息安全领域的热门技术，本文提出了一种新的基于离散小波变换和离散余弦变换的盲的水印图象嵌入算法，该算法首先对图象进行小波分解，对LL图象按照一定大小进行分块，然后对每一块进行离散余弦变换，把水印图象的值嵌入到变换后的系数上，最后再进行逆变换。把该算法能够经受住噪声、中值滤波、压缩、高通滤波、低通滤波等的处理，具有很强的鲁棒性。

A blind watermarking for digital image based on DWT and DCT

Digital watermarking is an effective method to solve problems of information security and copyright protection.It has been a hot technology in the field of multimedia information security.In this paper , a blind watermarking algorithm for digital image based on DWT and DCT is introduced. This algorithm manipulates the original image by DWT,then adds watermark onto the important wavelet coefficients located in the low frequency sub-band which is splited into blocks and manipulated by DCT.The experiment based on this algorithm demonstrates that the watermarking is robust to the common signal processing techniques including compressing, noise, low pass filtering, high pass filtering and medium filtering.