Research On Technology Of Digital Audio Watermarking

Nowadays information technology is progessing rapidly as the development in network technology and the continuous growth in various multimedia productions emerge simultaneously. As the effective method of copyright protection, the digital watermarking technology has acquired widely research and application.This dissertation selects audio as embedding object and takes binary image and audio signal as the watermark respectively. The main research work of the dissertation are as follows:1. Research on audio watermark algorithm in wavelet domain based on adaptive quantization. It is able to modify the quantization step and the embedding strength of watermarking adaptively according to the quantified signal to noise ratio, so the binary watermark image could be embedded in the original audio signal wavelet domain. Because the original signal is not needed when extracting the watermarking, it can be recovered by a blind way.2. Research on audio watermark algorithm based on pitch estimation. It is able to bring watermarking embedding in the discrete Fourier domain to effect by estimating the pitch of the original signal which determines the watermarking embedding position.The experimental result demonstrate that the watermark is imperceptible and the algorithms are robust to many basic signal operations. Both the algorithms use the method of quantization, so watermark value is extracted without access to the original audio. The blind watermark detection has very good practical value.