Watermarking Technology Based On Watson Model And Discrete Cosine Transform

Recently, with the popularity and the development of Internet, the copyright of digital products has aroused extensive interests, among which digital watermarking is deemed as an effective way for copyright protecting. It embeds the special information into digital products by the technique of data hiding, in order to mark and protect the copyright ownership. There are many watermark techniques in terms of their application areas and purpose. We can classify and analyze these methods from the various points of view. There two categories of watermark processing methods: spatial domain and frequency domain. Spatial domain methods are relatively simple, but frequency domain methods provide better robust to operations and attacks. Most recently proposed methods are frequency domain methods. We describe some popular methods in both spatial and frequency domain. This paper we describe watermarking technologies based on digital images. Firstly, we summarize concepts of information hiding technologies, then; we introduce characteristics of watermarking technologies and parameters which play important roles in estimating watermarking algorithms. And then, we specify some typical watermarking algorithms which had provided by foreign or civil scholars and give our own opinions. In this paper, we also show how to compute a perceptual matrix about the Just Noticeable Difference (JND) based on Watson model. Then, according to the matrix, we develop two new algorithms of digital watermark based on Discrete Cosine Transform. In the last part of this chapter, we use some experiments to validate our algorithms.At last, we introduce some functions of the software which we have designed according to the two algorithms to embed watermark to a digital image.