Watermarking Research For Forgery Prevention Of Printed Brands

Digital watermarking is a kind of technique that embeds a imperceptible mark in digital media. When it is needed, the embedded label information can be extracted for validation via a certain scheme, which provides a very effective solution on the tort issue of digital products. Therefore, it has become an nowadays research hotspot.Copyright protection and forgery prevention and detection are of great social importance. In the past, the algorithms of Digital Watermarking are designed mainly for the copyright protection of digital media, not for forgery prevention. In this paper, we summarize the application background and research state of digital watermarking press work forgery prevention, and then mainly focus our research on the digital watermarking algorithm based on spatial correlation detection. And, with the reuse methodology, we implement the Portable Watermark Detector based on FPGA. The valuable research fruits are as follows:1. After analyzing the reasons that print-scan process brings distortion to image, and doing lots of experiments, a spatial watermarking algorithm is proposed. Based on orthogonal experimental design method, the optimization of the parameters that affect the intensity of the embedded watermarking is realized to satisfy the requirements of forgery prevention for printed brand, that is to say the digital watermark is robust to one cycle print--scan and fragile to two cycle print--scan.2. Based on our scheme, we implement the Portable Watermark Detector based on FPGA. Meanwhile we transfer the Watermark Detect algorithm to an IP core which make this technology be easily used in lots of fields. We also talk about defects of the system and propose further improvement thoughts.