ABSTRACT
The typical DCT digital watermark embedding algorithm limit the embedded watermark signal volumes because the embedded watermark signal frequency position is fixed. On the other hand it limits the watermark embedding volumes, namely the watermark capacity. Therefore, the improved digital watermarking embedded system, the embedded position is not the particular frequency location, such as high low frequency watermarking embedding point location for encryption, and instead of
1 INTRODUCTION
In the process of transformation from traditional business to electronic business affairs, a large number of excessive electronic document will appear, such as a variety of paper bill scanning image. Even the network security technology is mature, a variety of electronic bill also need some no password authentication method. Digital watermarking technology can provide invisible certification mark for various bill, so greatly increase the forge difficulty[1-5].
