Document Watermarking Robust to Copying

In general, a duplicated or tampered one of document can be obtained by duplicating machine. How to distinguish watermark quality from the first printing document and the duplicated or tampered one? In this paper we introduce a document watermarking arithmetic which is robust to copying. The arithmetic is based on the FMT transformation. The document is regarded as one image and is embedded 8 digitals. Experiments results show that the scheme can resist first printing and scan process. Furthermore watermark cannot be extracted from the duplicated or tampered one.