The Study Of Watermarking Arithmetic For Halftone Image Based On Human Vision System Model

With the development of the digital technology and computer network technology in these years, we can get and transmit digital information more conveniently and quickly, and these have done a great favor to the communication of multimedia information, at the same time, the illegal copy and communication of multimedia information has become more and more common than before. So, the copyright protection of multimedia information has become one important and urgent research task. There are many different digital watermarking technology be suggested to resolve the problem of copyright protection of multimedia information (such as, digital image).As the use of digital media has become more and more popular, there are still many information be existed and transmited in printing way for a long time in future. The copyright protection of these paper media information also very important compare with digital media, but a majority of the existing image digital watermarking technology be used to embed watermarking in continue-tone image for the purpose of image copyright protection. When we output the paper media image from digital continue tone image, the halftone arithmetic should be used to process the continue- tone image.The thesis discussed the digital watermarking technology which can embed watermark in halftone image in the process of halftoning. We purpose the digital watermarking arithmetic based the human vision system model which can minimize the visual error between the embed watermark halftone image and the original continuous-tone image using iterative binary search method. The arithmetic can embed many information to halftone image under the precondition of watermarking invisibility, on the other hand, the extract of watermarking is accurate. All experiment indicate that this arithmetic can embed more information than other arithmetic and has strong robustness, so the arithmetic can resist unconsciously or intentionally attack .which caused by printing, scan, dirty, clip, etc., at the same time, the watermarking embed in halftone image using this arithmetic has the advantage of invisibility, high vision quality of halftone image and high practical application value.