基于人类视觉系统的小波域彩色图像水印算法

为提高水印的鲁棒性和透明性，提出一种基于小波变换域的水印算法。提取RGB图像的绿色分量并对其进行3层小波变换，将置乱处理过的水印图像嵌入已排好序的小波域水平方向细节子带大值系数中，通过计算所需的JND阈值，调整水印嵌入强度。实验结果表明，该方法具有较好的鲁棒性及水印透明性。

Color Image Watermark Algorithm in Wavelet Domain Based on Human Visual System

Aiming at the problem of how to improve the robustness and transparency of watermark,this paper proposes a new watermark algorithm based on wavelet domain.The green component of the color image is extracted and then is transformed with three layers of wavelet transform.The scrambled watermark image is embedded to the already sorted wavelet coefficients of maximum coefficient of high frequency sub-bands.The Just Noticeable Difference（JND） threshold is calculated to adjust watermark embedding strength.Experimental result shows that this method is of better robustness and it takes the transparency of watermark into careful consideration.