基于多数字基整数和小波域JND的多重数字水印

提出了一种新颖的在小波变换域中嵌入多重数字水印的算法。该算法通过利用人眼的视觉特性，计算小波域临界可见误差JND门限，选择加载水印信息的小波系数和控制加载的水印强度。通过引入多数字基整数系统，选择舍适的JND门限作为该系统的基底，将水印的小波系数表示为多数字基整数，最后转化为修改一组宿主图像的小波系数的幅值，从而实现水印嵌入算法．实验结果表明，该算法实现的数字水印对于图像压缩、图像剪切等常见图像处理有很好的鲁棒性。

Digital Watermarking Via Multiple-based Number and JND Threshold in Wavelet Domain

In this paper, a novel method embedding multiple watermarks into the owner image for copyright protection is proposed. Calculating the JND thresholds in wavelet domain based on visual masking effect of human visual system, we can determinate the locations and strength for watermarks embedding. Changing the wavelet coefficients without excess the range of the just noticeable difference, the image is watermarked. The multiple based number system is introduced and a suitable group of JND thresholds is chosen as the system's basis. Finally, the information of the watermarks is skillfully converted into values to be embedded in the wavelet coefficients of the owner image. Experiments show our watermarking method has a good robustness to image processing such as image compression and image cropping, etc.