Digital Halftone Watermark Based On Hybrid Halftone

With the development of technology continuously improves the quality and function scanners, digital cameras, photocopiers and other image acquisition equipment; it's very easy to use these engaged in illegal copying, forged or counterfeit acts in disguise for criminals. The protection of digital works, it's proposed digital watermarking technology, but copyright protection for the printed works has many loopholes, it's not only because digital intermedium and paper intermedium has different characteristics, but also include the digital image halftone technology. How to achieve the optimal combination of the two technologies in the printing works in order to achieve copyright protection is a current hotspot.In this paper to address this issue by analyzing AM/FM halftone of their own trait, a security functions in a hybrid halftone watermarking technology is proposed. The algorithm generating templates during halftone process, for each template gives different halftone method, and use the different AM / FM dot copy reaction to extraction the watermark, a hybrid halftone is produced during the embedding watermark, and make a watermark security features watermark paper, to extract information watermark just scan or copy watermark paper. Test results shows that the algorithm has some of the security functions, embedding algorithm is simple and efficient, and watermark extraction algorithm is different from other complex extraction process, after copying or scanning can extract watermark.In this paper, the algorithm was discussed in detail and through extensive testing algorithm to improve and detailed analysis. Finally, gives a conclusion to the algorithm along with its application and development prospects to the future.