关键词: 数字水印 盲检测 扩频通讯 随机置乱 锐化滤波

Abstract:

Random permutation and sharpening are basic methods of image processing. In some digital image watermarking systems, if the original image is pre-pro essed with random permutation before embedding and the watermarked image is pre-processed with sharpening before detection, the performance of watermark ing can be improved, which means the images can look better, or the veracity rate of detection is higher. In this article, this scheme is validated in Bami＇s semi-blind watermarking system. In addition,a new watermarking scheme is designed in which both permutation and sharpening are used to insure th e performance. In this scheme, watermarking is embedded into the difference of neighboring blocks＇ DCT coefficients. The experimental results show   t this scheme is robust to various image processing.

Key words: digital watermarking, blind detection, spread spectrum communication, random permutation, sharpening