Image Watermarking Algorithm Against Jpeg Attacks

With the rapid growth of Internet technologies and extensive use of multimedia data, the enforcement of multimedia copyright protection becomes an important issue. Digital watermarking is viewed as an effective way for intellectual property right protection of multimedia data. Firstly, This paper introduces the development of digital watermarking technologies, describes the basic characteristic, classification and application fields of digital watermarking. It then formulates the generic model of digital watermarking algorithms based on images and expatiates the main parts of the model. This paper is focused on images watermarking algorithms. Two new algorithms based on spatial-domain and transform-domain respectively are presented as follow: A digital watermarking algorithm based on Most Significance Bits (MSB) of images is proposed. As few digital watermarking algorithms based on spatial-domain can survive after familiar attack, researchers are no more interested in them as ever. One of the algorithms is based on Least Significance Bits (LSB), which is not good at embedding space and robustness, especially unable to resist JPEG compressing. Considering the change of MSB often greatly affects the quality of images, few researchers turn their attention to MSB. That's why few papers about MSB can be found now. Here a watermarking algorithm based on MSB is proposed. It works by using some special color partial-value. In addition, the original image is needed in detecting phase. Pilot study shows that the proposed algorithm has some robustness to JPEG compression. A blind digital watermarking algorithm based on Hierarchical Discrete Cosine Transform (HDCT) is proposed. Digital watermarking algorithm based on Discrete Cosine Transform (DCT) transform-domain has been widely studied for DCT is used in international compressing standard and is helpful to create robust watermarking algorithms. Research shows that the reorganization of DCT can be taken as multiresolution wavelet decomposition, which can combine the characteristics of human vision and...