时域抗JPEG压缩数字水印算法的设计

本文首先介绍数字水印的含义、用途和基本特征;然后详细说明了为了隐藏秘密信息,防止针对图像有意或无意的攻击,设计了基于时域的抗JPEG压缩数字水印算法,并讨论了水印嵌入过程中各个参数在调节水印不可感知性、鲁棒性和容量3者关系时的作用;最后,本文列出了不同攻击下水印嵌入的效果和水印提取的结果.其结果表明,该方法可以针对所经受的JPEG压缩程度以及其他攻击的强度,自由调节各个参数,以达到水印不可感知性、鲁棒性和隐藏信息容量之间的平衡,并保证隐藏信息的完整性.

Design of digital watermark algorithm in time domain to resist JPEG compression

This paper first briefly introduced the meaning, use and essential feature of digital watermark. Then a digital watermark algorithm based on the time-domain to resist JPEG compression was described in detail, which was designed to hide secret information into a image and to resist the attacks whether intentional or unconscious. And in succession this text discussed the meaning of each parameter in the course of watermark embedding, and their effect to adjust imperceptibility, robustness and information capacity of digital watermark. Finally, this article utilized the MATLAB simulation and presented the effectiveness on different attacks and the result of digital watermark extraction. It shows that this method can adjust the parameters in embedding secret information according to the degree about JPEG compression, noise pollution, blur attack, contrast change and etc to keep the balance among imperceptibility, robustness and information capacity of digital watermark, and ensure the integrality of the hiding information.