一种低复杂度的基于小波的彩色图像水印算法

Simple Color Image Watermarking Algorithm Based on Wavelet

根据图像小波变换系数的特点,提出了一种双彩色水印新算法:把彩色宿主图像的R,G,B分量分别经过p级小波分解,使它们各自的低频系数LLp个数等于水印的尺寸大小,然后将R,G,B分量的LLp系数分别加上加权后的彩色水印R,G,B分量的灰度值,将这些变化了的低频系数和没有变化的高频系数一起经过小波逆变换即得彩色水印图像。这种水印算法复杂度低,实验证明该水印具有较好的不可见性、鲁棒性。

Based on performances of coefficients of wavelet transform, a new double color digital watermarking algorithm is proposed. In this paper, RGB elements of host image are decomposed into p levels solely with wavelet, making the number of LLp coefficients equal to the size of digital watermarks, then each LLp coefficient of RGB elements is added by scaled gray levels of corresponding RGB elements of watermarks and the result is taken as new LLp coefficients of host image, and then we take the IDWT of the modified DWT coefficients and unchanged coefficients to form color watermarked image. The algorithm is simple and performances of the proposed watermarking are good in transparency and robustness.