A Novel Audio Watermarking Based On Synergic FFT and DWT

With the recent development of information technology and computer network, digital format of data has become more and more popular. However, a major problem faced by digital data providers and owners is protecting data from unauthorized copying and distribution. As a solution to the problem, digital watermark technology is now attracting attention as new method of protection against said unauthorized copying and distribution. The aim of the digital audio watermarking is to take prespecified data that carries certain information and hide it within the audio stream such that it is not audible to the human ear (i.e., transparent) but at the same time renders the file more resistant to removal (i.e., robust)(Katzenbeisser et al,2000). In this paper, we propose a new audio watermarking method, in the way that human auditory system is not sensitive to it. The proposed method can produce the watermark sequnce by a shift register and embed it in to levels 3-4 of wavelet transform. The extraction algorithm of the proposed method extracts two watermark sequences from watermarked data. The final watermark sequence will be generated again by a shift register. The experimental results show that the proposed method is very robust to noise. In order to evaluate, the proposed method is compared with the methods based on FFT, Echo (Kim et al, 2003) ( Kim et al,2004)