Against Printing And Scanning Digital Watermarking Technology

With the development of computer technology and the advancement of digital media storage and transmission, it is a serious challenge that protecting the copyright of digital media. And at the same time, it is easy to break through information security system. The tradition information encryption technology is easy to be cracked under the open network environment. And forgery commodities and certificates can be seen everywhere. So Digital Watermarking(DW) develops quickly. It's a new technology of copyright protection, information hiding, forgery prevention and detection.Digital Watermarking is a digital signal which is embed into digital media , can be detected or extracted and does not affect the normal use of the digital media. The technology makes digital media has the function of copyright protection and information hiding and anti-counterfeiting printing by embedding a little information into it.Copyright protection and forgery prevention and detection are of great social importance. In the past , the algorithms of Digital Watermarking are designed mainly for the copyright protection of digital media, not for forgery prevention. The main reason is that printing and scanning maybe affect the Digital Watermarking and make it can not be detected or extracted correctly. Aiming at the problem of printing and scanning , the paper designs a new Digital Watermarking algorithm . It takes use of pseudo-random technology, dynamic adaptive technology, multi-channel technology, random position embed technology and so no. So the Digital Watermarking can resist the physical process of printing and scanning. At the same time, the watermark is binary image which includes a great deal of information, such as personal ID, secret information, even a piece of map . So the technology can apply to not only copyright protection ,but also information hiding and forgery prevention.The experiment results show that the proposed algorithm can resist cropping operation, scaling operation and JPEG compression, printing and scanning. Comparing with other forgery prevention and detection technology, the performance of forgery prevention is proved better. The algorithm described in the paper reduced the cost of forgery prevention , and enlarges the application fields. It will bring great social benefits and economic benefits.