A Blind Digital Watermarking for PDF Document
Qing Chen, Qi Wen Hu, Shao Feng, Ze Fu · Applied Mechanics and Materials · 2013
In this paper, a text blind watermarking is proposed and implemented for copyright protection. Based on the characteristics of PDF format, this algorithm uses character spacing coding throughout whole PDF document to embed watermark into it. Robustness and security is further increased by using synchronous coding, cycle encryption and majority decision. Watermark embedding and extracting are implemented under the software environment of VC++ 6.0, and performances are tested and analyzed. Experiments show that the algorithm has good transparency, large capacity and good robustness. It can apply to both of Chinese and English PDF documents.