基于小波域的彩色图像盲数字水印算法

稳健性是图像隐藏水印最基本的要求之一,而水印的嵌入强度、嵌入位置影响水印的稳健性.文中提出了一种基于离散小波变换的彩色图像盲数字水印算法.水印采用文本图像水印,为了保证水印的安全性,对水印图像进行混沌加密,将原始载体图像的蓝色分量进行3级小波变换,将加密后的水印自适应地嵌入到蓝色分量的最低层低频逼近的每一个系数中,水印嵌入强较大,而现有基于小波变换的算法大多将水印嵌入在各个方向的中频或高频系数中.在检测时,不需要原始图像,是盲检测.实验结果表明该算法很好地保持了图像质量,对常见的图像处理显示了很强的鲁棒性.

A Blind-Watermark Algorithm Based on Wavelet Domain for Color Image

Robustness is one of the most basic requirements for invisible image watermark.Embedding strength and embedding location all affect robustness of watermark. In this paper,a new watermark algorithm for color images based on discrete wavelet transform (DWT) is proposed.The watermark used here is a text watermark. To ensure the security,first,the watermark should be encryptedThen,the 3-level DWT is applied to the blue component of host image . Then the watermark image is adaptive embedded into each lowest approximation coefficients of multiresolution representation of blue component of the original image, and the embedding strength is greater while most of other DWT methods embed watermark into the middle or high frequency components. Detecting procedure doesn't need original host image. Experimental results show that the proposed algorithm keeps the quality of the image well and is robust enough to common image processing operations.