Researches on the Information Hiding Technology Used in Paper-Based Document Images

摘要

With the rapid development of the information technology and digital image copy devices, the information carrier shows off diversified trends. However paper media still play an important role in many areas serving as information carrier, and correspondingly the information security of paper documents faces great challenges. So how to solve the information security problems of paper media has become the hottest research topic. This paper proposes an information hiding method used in printed documents image based on the screen dots modulating shade composed of a large number of randomly arranged screen dots. These dots are classified into coding dots, anchor dots and perturbing dots respectively. Experimental results show that screen dots modulating shade using our method has larger information capacity and also has strong robustness against the attacks of print-scan processes. Moreover, this technology also can be widely used in many other areas, such as anti-counterfeit printing, anti-copy, document content tamper-proofing and document image retrieval etc.