一种基于双正交小波变换的图像数字水印算法

利用双正交小波变换在图像处理中的良好性质，提出了一种图像数字水印嵌入算法。在此算法中，对水印信号进行了置乱和逼近两个步骤的预处理，所生成的两个密钥确保了水印的安全；在嵌入水印时由于采用了取代的方式，使得提取水印时不需要原始图像的参与。实验表明，该算法能够抵抗诸如叠加噪声、JPEG压缩、几何裁剪以及滤波等常见的攻击，具有较强的鲁棒性，是一种行之有效的水印方法。

Algorithm for Image Digital Watermarking Based on Biorthogonal Wavelet Transform

Using the excellent character of the biorthogonal wavelet transform in image processing,we put forward an algorithm of embedding the image watermark in a digital picture.The algorithm will produce two independent keys,which can ensure the security of the watermarking.Moreover,the original image needn't exist when the watermarking is being drawn,because we select the manner of replacement to embed watermarking.Experimental results show that this method is invisible and robust against some usual signal processings such as noising,compression,filtering and cutting.So it is effective and practical.