基于人类视觉系统和离散小波变换的彩色图像水印

摘要

为了扩大数字水印的适用范围,提出一种基于人类视觉系统(HVS)和离散小波变换(DWT)的彩色图像数字水印算法.首先利用混沌加密算法把一个有意义的二值图像加密成水印；然后将彩色图像从RGB色彩空间转换到YCbCr空间,提取y分量,对Y分量进行一级离散小波变换；最后求出低频分量LL1的视觉掩蔽值,根据视觉掩蔽值,将水印嵌入到彩色图像的Y分量的低频小波系数域上.实验结果表明,该算法具有较好的不可见性和鲁棒性.与以往的基于YCbCr颜色空间的算法相比,该算法具有更好的不可见性和鲁棒性.%In order to extend the range of applying of digital watermarks, this paper introduced a watermarking algorithm for color image based on Human Visual System ( HVS) and Discrete Wavelet Transform ( DWT). First, a meaningful binary image was encrypted by chaotic encryption algorithm to form watermark. Then the color image was converted from RGB color space to YCbCr space; the Y component was extracted and one level discrete wavelet transform was executed. Finally, the visual masking value of LL1 was got. According to the visual masking value, the watermark was embedded into the low-frequency wavelet coefficient domains of Y components of color image. Experimental results show that the proposed algorithm has better invisibility and robustness than the algorithm based on YCbCr color space.