Digital Image And Video Watermarking Algorithm Research On Discrete Wavelet Transform And Human Visual Syetem

With the rapid development of information technology and computer network technology, multimedia production and distribution is digital and network. Digital multimedia data (such as image, text, audio, video, 3D model, etc.) storage, copying and dissemination has become extremely easy, but the piracy problem has become an increasingly serious social problems and must be resolved. As an important and effective solution to protect the intellectual property rights of digital multimedia, a digital watermarking is information that is imperceptibly and robustly embedded into the multimedia data, has become a hot area of information security at home and abroad.This thesis reviews the research status, the general model, the basic requirements and typical algorithms about multimedia digital watermarking technology, then for the copyright protection of digital image and video, one binary image chaotic encryption algorithm based on chaos and Arnold transform, one image watermarking algorithm and one video watermarking algorithm based on discrete wavelet transform and the characteristics of the human visual system are proposed respectively.(1)In order to improve the security of watermarking and the ability to withstand malicious attacks, a binary image scrambling encryption algorithm based on chaos and Arnold transform was proposed. Firstly the watermarking image pixel value was changed by using chaotic sequence which is generated by one-dimensional chaotic map, and then the changed watermarking image was scrambled by Arnold transform. The algorithm is simple, less computation, and has high security.(2)An adaptive algorithm for image watermarking is proposed based on discrete wavelet transform(DWT).By multi-resolution decomposition technique, the decomposed watermarkings of different resolution are embedded into the corresponding resolution of the decomposed original image. The embedding strengths are adaptively adjusted by the human visual system masking features of texture, luminance and frequency, the watermarking can be extracted without the original digital image signal. Experimental results show that the embedded digital watermarking is invisible and robust to image processing such as JPEG 2000 loss compression, average filtering, Gaussian filtering, Gaussian noise, salt and pepper noise and the shearing. It is more robust against common attacks than traditional algorithm based on DWT low-frequency sub-band.(3)An adaptive video watermarking algorithm is proposed by using the visible binary image as watermarking based on three-dimensional discrete wavelet transform(3D DWT) and human visual system. First, the watermarking is preprocessed by using chaotic encryption and Arnold scrambling and the algorithm partitions the video sequence into different scenes by using video scene shot segmentation method based on directional empirical mode decomposition (DEMD),some of which are selected with a key to perform 3 levels 3D DWT. Then, for the low-frequency sub-band by dividing different areas, the watermarking embedding strengths are adaptively adjusted by using the human visual system masking characteristics of texture area and motion area. Experimental results show that the proposed algorithm is well invisible and robust to attack such as brightness change, Gaussian noise, salt and pepper noise, median filtering, frame loss, frame averaging, frame replacement, and MPEG compression.