Document electronic seal system based on digital watermark and DWT technology

Safety and genuineness protection of the documents while traveling over the internet is very crucial. In this paper, a novel watermarking scheme for electronic seal based on discrete wavelet transform (DWT) is proposed. The theory of digital watermark based on DWT for electronic seal is discussed. The watermark signals are considered as a binary sequence embedded to the high (HL and HH) frequency band of the document in DWT domain. The algorithm of how to embed and extract the watermark is shown in the paper. The experimental results demonstrate the efficiency of the proposed scheme, which fulfills the strict requirements of electronic seal and is practicality perfect by means of good balance between transparency and robustness.