一种基于数字水印的印刷品防伪方法

提出一种基于数字水印技术的印刷品防伪算法.在图像打印前,水印经Arnold置乱后嵌入到原始载体图像的Hadam ard变换域中;在检测数字水印时,首先对印刷品扫描图像进行几何矫正,利用边缘检测、Radon变换等方法检测图像旋转角度,将其转正,用三次内插法对图像重采样,恢复图像的原始尺寸.最后从矫正后的图像中提取水印.实验结果表明,这种算法具有较好的安全性、鲁棒性,在防伪效果上取得了满意的结果.

A forgery detection method in printed materials based on digital watermarking

The paper proposed a forgery detection method in printed materials based on digital watermark.First,the watermark was scrambled by Arnold transform and embedded into the Hadamard domain of the image.When extracting watermark,the scan image was firstly rotated to the correct position,which rotate angle was detected by edge detecting and Radon transform.The image was secondly restored to the size of original image by the cubic convolution resample method and transformed to Hadamard domain for extracting the watermark.After re-scrambling the extracted watermark,the embedded watermark was detected.The results show that the algorithm is security,robust,and effective on the forgery detection in printed materials during the printing and scanning process.