Research On Vector Graphics Digital Watermarking

Digital watermark technology is an important branch of information hiding. To achieve protection of copyright, authenticity certification, piracy tracking and provide additional information, it embedded certain identifying information in the digital multimedia resource. In recent years, a variety of different forms of digital watermarking technology has been widespread concern and achieved some excellent results.Vector, which belongs to the field of digital image as well as raster images, is a special file format. Because of the characteristic of amplification without distortion, small file size and high precision, it is widely used in map search, engineering drawing, logo and design drawing and so on. Therefore, copyright protection of vector graphics is important. Vector watermarking is very different from raster image watermarking, but the research of digital watermarking for the vector is not much.This paper first introduced the basic framework, application, classification and evaluation of digital watermarking technology, then the features of vector graphics and the current research situation of digital watermarking for vectors. For different applications, two different digital watermarking algorithms were proposed, and the research results are as below:(1) To protect the copyright of vector graphics, an algorithm based on singular value decomposition was proposed. The algorithm, which focused on robustness, combined the anti-disturbance of singular value decomposition with a new pretreatment method. The experiment results showed that this algorithm worked well against some attacks.(2) In the environment requiring high precision, any small error caused by embedding watermarking is not allowed, so this paper proposed a reversible watermarking algorithm based on difference expansion and shift. In the improved algorithm, the watermark is embedded into both the difference-expansion vertices and difference-shifting vertices, so the embedding capacity is much higher. It achieved authenticity certification and could recover the original data after abstracting the watermark.(3) Compared the two proposed algorithms from both the design and performance, and discussed the focus of watermarking algorithms for different applications...