Based On The Transform Domain Digital Watermarking Algorithm

Digital watermarking has been more than ten years of history, annexed by watermarking the media division, which can be divided into three categories: image watermarking, audio watermarking, video watermarking. Image watermarking algorithm is the basis for audio and video watermarking, which can easily be applied to audio and video watermarking, while transform domain watermarking algorithm is the core of the current image watermarking algorithm, therefore, this paper options Transform domain watermarking algorithm for the study. This article researches the following three kinds of watermarking algorithms:A spread spectrum watermarking algorithm based on orthogonal Walsh code.This algorithm grounded on code division multiple acess principle. The watermarking is modulated by three orthogonal Walsh codes, and then the compound signal is embedded in the low and middle coefficients of original image's DCT domain. This algorithm is essentially a multi-channel embedded watermark, to strengthen in the reliability of communication channel. Compared with the usual direct spread spectrum algorithm, the simulation results show that this algorithm is more robust and transparent. As the watermark is a pseudo-random sequence,the watermark capacity is relatively small.Wavelet domain watermarking algorithm combined zero-tree wavelet coding algorithm with HVS.The algorithm is based on wavelet transform.At the beginning ,the watermark image scrambled take direct sequence spread watermark sequence method extended signal, and then embedded into a group of selected wavelet coefficients of importance, where the critical embedding strength can be seen from the wavelet domain Error JND threshold decision. the simulation results show this algorithm achieve a good balance between invisibility and robustness,at the same time, the process of embedding the watermark saves much time for the location selected in the embedded zero-tree coding. This algorithm uses binary image as a watermark and watermark capacity expands, but it still belongs to a simple transform domain watermarking algorithm and sensitive to geometric attacks.The digital watermarking algorithm combined SVD and multi-wavelet transform.The singular value decomposition algorithm and multi-wavelet transform are organically combined. Using Arnold transform scrambles the embedded binary watermark, which eliminates the correlation between pixels and enhances the anti-attack performance of the algorithm. When embedding watermark, the singular values of watermak scrambled are embedded into the image three-layer multi-wavelet transform of the IF area, and the nature of the watermark embedding strength is in accordance with IF block region.To obtain two values of the watermark,watermark extraction makes a good use of the nature of of binary images.The simulation results prove that the algorithm proposed in this paper is not only good transparency but also to deal with the common watermark attacks has strong robustness, while shear, rotation, geometric attacks have good stability.