Research Of Digital Watermarking Technology Based On The Still Image

The digital media has become a main way for information communication along with the wide use of network. At the same time, multimedia information security problems including copyrights piracy emerged as side effects of the popularity of digital representation and distribution over network. Information hiding, also called Sicganography , digital watermarking technology provide novel ways to solve these security problems for multimedia information. In this dissertation, we study the technologies and application of multimedia information security in the area of digital watermarking. The main contributions of this dissertation are:A Newly Watermarking Algorithm With Gray-level Image based on DWT And SVD is proposed: Now, most of the watermarking algorithms hide the random signal or two-value image into the image; only a few watermarking algorithms hide the gray-level image into the image. In my dissertation, we study the algorithm that hides the gray-level image into the image and gain some result. The algorithm that we study is based on DWT and SVD. The main merit of the algorithm is the capacity of the watermarking information that is hid into the image is much more than the capacity of the random signal and two-value image. The experiment based on this algorithm demonstrate that the watermarking is robust to the common signal processing techniques including compressing, noise,low pass filter,high pass filter and median filter.A blind watermarking for digital image based on DWT and DCT is proposed: Now , in the most of the watermarking algorithms , the detection of the watermarking need the original image, so the practicability of the watermarking is not good . In order to strengthen the practicability of the watermarking,we proposed a blind watermarking algorithm for Digital Image Based On DWT and DCT. This algorithm manipulate the original image by DWT, then adds watermark onto the important wavelet coefficients located in the low frequency sub-band which is splitted into blocks and manipulated by DCT. The experiment based on this algorithm demonstrate that the watermarking is robust to the common signal processing techniques including compressing, noise,low pass filter, high pass filter and median filter.