Research On Digital Audio Watermarking Algorithm Based On Auditory Model And PSO

The rapid development of multimedia technology and Internet promotes the transmission and replication of multimedia information,but the subsequent piracy and patent infringement activities are increasingly rampant.In order to solve information security issues,digital audio watermarking technique was proposed and has been widely used in copyright protection,content authentication and integrity checking,digital fingerprinting,broadcast monitoring,covert communications and so on.Although current audio watermarking algorithms have obtained good robustness and imperceptibility,most of them have the drawback with the payload.Besides,most watermarking algorithms based on SVD have a good robustness,but there are still some disadvantages in many aspects.(1)An adaptive audio watermarking algorithm in the hybrid domain is proposed,the scheme jointly exploiting the discrete wavelet packet transform(DWPT)and psychoacoustic model to perform large-capacity audio watermarking without introducing perceptible distortion.Each audio frame was decomposed into 26sub-band signals by using DWPT,then we apply DCT to wavelet packet coefficients of each sub-band and calculate the masking threshold.The masking threshold of each sub-band was used to seek suitable segments and positions for watermark embedding,according to the embedding strength obtained from psychoacoustic model,the algorithm adaptively control the audibility of introduced distortion for embedding the watermark.The binary image watermark was embedded into the block middle-frequency and low-frequency DCT coefficients according to quantization index modulation,the extraction was executed blindly.Experimental results show that our scheme achieves a good trade-off between robustness,imperceptibility and payload,the watermark capacity range from 576.7bps to 689.5bps,the hidden watermark data is robust to additive noise,re-quantization,re-sampling,low-pass filtering,and MP3 compression.(2)An audio watermarking algorithm based on DWT-SVD and particle swarm optimization is proposed in this thesis.In the algorithm,the rearranged audio signal was partitioned into blocks,and then the vector was generated by selecting the biggestsingular values after performing SVD on these blocks.Then the synchronous code and watermark were embedded into the approximate components obtained from the DWT decomposition of the vector by quantization index modulation process.The algorithm makes full use of the the multi-resolution characteristic of wavelet transform and the stability of SVD transform.In the process of watermark embedding,an optimization procedure of audio watermarking was developed by using particle swarm optimization(PSO)automatically to determine the optimal watermarking strength of watermarking algorithm,which can optimally balance imperceptibility and robustness against both common signal processing and desychronization attacks.