Reserch On Binary Document Image Digital Watermarking

With the rapid development of computer networks and communication technologies, digital media (including digital images, digital audio, digital video) has been widely used.Digital media, information security and intellectual property protection certification have become more urgent, which has become a very important research questions in the digital world. Digital watermarking technology is a type of effective copyright protection technology. Currently, most of the digital watermarking research works are focused in the areas of color images, video, audio. Because of the features of the text itself, some current text watermark algorithms have many defects, such as lack of robustness, concealment not so good, and so on.In this paper, the author research the defects of the existing text watermarking technology research, the main research topics include the following aspects:(1)Firstly comprehensive study of the existing document watermark algorithms, as well make analysis.(2)Introduced the human visual model algorithm and its application. According to the characteristics of text and image, we summarized a flip watermark based on block pixel scheme. The method manipulates "flippable" pixels and uses shuffling to embed a significant amount of data without causing noticeable artifacts. The extraction of the hidden data does not require the original image. With the problem of pixels are close to each other s, we present a measure based on the reciprocal of distance that is straightforward to calculate. Our results show that the proposed method can effectively improve the watermark visual effect.(3)We propose a novel double domain watermarking. The watermark pattern is generated as a transform domain signal, and adapted to the characteristics of human visual system by adjusting the localized embedding strength in the spatial domain. Watermark extraction can be operated by applying a correlation based detector in either of the two domains. The approach exploits the information of the two domains for embedding, but avoids transforming the original binary image directly, which does not cause unacceptable loss of watermark.This paper realized the algorithm, and a large number of attacks experiment. The experimental results show that the the DDW algorithm manifests the good robustness against common image manipulations, geometrical attacks as well as print-scan process.