Study On Adaptive Audio Watermarking Algorithms

The rapid development of digital and network technology makes the digital media's production, acquisition and transmission become more and more convenient, but it puts forward the new challenge to the protection of digital product's copyright, because in the "digital world" the operation of copying, forging and tampering has become very easy. Digital watermarking technology which is one of international academic research focuses can provide effective solutions for the protection of digital products's copyright. As a major digital media, digital audio products's copyright protection issues needs to be resolved urgently, and digital audio watermarking technology becomes an important research direction of digital watermarking.Adaptive audio watermarking algorithm can adaptively select the embedding location, intensity and other parameters of the watermark based on the characteristics of the local audio. It is conducive to the practical application of watermarking algorithm. This paper mainly focuses on designing adaptive digital audio watermarking algorithm, the main work is given as follows:1,Based on psychoacoustic model, an adaptive audio watermarking algorithm has been proposed. Firstly, the audio signals is divided into multiple sub-bands by using of filter banks, and then the watermark is embedded by quantifying the Direct Current (DC) coefficient of discrete cosine transform in the sub-band domain. In this paper, the embedding location and strength in each sub-band was determined by the sub-band masking threshold, thus the watermark is embedded adaptively. Simulation results show that the proposed algorithm is robust against some common attacks such as adding noise, low-pass filtering, re-quantization, re-sampling, MPEG-1 Layer III (MP3) compression.2,A new audio watermarking scheme based on Walsh Hadamard Transform (WHT) and Discrete Wavelet Transform (DWT) is proposed. The features of the proposed scheme are as follows:(1) the multiresolution characteristics of DWT and the energy-compression characteristics of WHT are combined to improve the transparency of digital watermark; (2) the watermark is embedded into the low frequency components by adaptive quantization based on SNR; (3) the scheme can extract the watermark without the help of the original digital audio signal;(4) the proposed watermarking scheme is not only robust against common attacks such as various signal processing such as noise adding, low-pass filtering, resampling, requantization, random cropping, MP3 compression and echo adding, but also robust against various attacks based on cooledit and stirmark platform.