针对多媒体资源的版权保护问题,结合离散小波变换和奇异值分解技术的优点,提出了一种基于离散小波变换和奇异值分解的图像水印算法.该算法首先将原始宿主图像分解为4个频带(LL、HL、LH和HH),再对水印图像做奇异值分解,并修改宿主图像的离散小波变换系数和水印图像的奇异值.实验结果表明,该算法不仅具有良好的不可见性,而且对诸如滤波、几何攻击、JPEG压缩和旋转等常见的图像攻击具有很强的鲁棒性.
A algorithm of image watermarking based on the discrete wavelet transform(DWT) and singular value decomposition(SVD) is proposed for copyright protection of multimedia resources.In this algorithm,after decomposing the original host image into four bands(LL,HL,LH,and HH),we apply the SVD to watermark image,and modify DWT coefficients of the host image with the singular values of the watermark image.Experimental results show that this new image watermarking algorithm has a good imperceptibility of embedded watermark image and robust against common attacks such as filtering,geometric attack,JPEG compression and rotation,etc.