Robust high-capacity audio watermarking based on FFT amplitude modification

This paper proposes a novel robust audio watermarking algorithm to embed data and extract it in a bit-exact manner based on changing the magnitudes of the FFT spectrum. The key point is selecting a frequency band for embedding based on the comparison between the original and the MP3 compressed/decompressed signal and on a suitable scaling factor. The experimental results show that the method has a very high capacity (about 5 kbps), without significant perceptual distortion (ODG about -0.25) and provides robustness against common audio signal processing such as added noise, filtering and MPEG compression (MP3). Furthermore, the proposed method has a larger capacity (number of embedded bits to number of host bits rate) than recent image data hiding methods

Employing Psychoacoustic Model for Digital Audio Watermarking

This thesis discusses about digital audio watermarking by employing psychoacoustic model to make the watermarked signal inaudible to the audience. Due to the digital media data able to distribute easily without losing of data information, thus the intellectual property of musical creators and distributor may affected by this kind of circumstance . To prevent this, we propose the usage of spread spectrum technique and psychoacoustic model for embedding process, zero-forcing equalization and detection and wiener filtering for extracting process. Three samples of audio signal have been chosen for this experiment which are categorized as quiet, moderate, and noise state signal. The findings shows that our watermarking scheme achieved the intended purposes which are to test digital audio watermarking by employing psychoacoustic model, to embed different length of messages to test on accuracy of extracted data and to study the suitability on using hash function for verification of modification attacks

Hardware Implementation of Audio Watermarking Based on DWT Transform

Presently, the duplicate copy of an audio can be generated with great ease using some smart devices, and transmitted over the internet which raises concern over copyright and privacy. Digital audio watermarking is a procedure to insert some data bits known as watermark into audio signal. Then the audio with watermark is to be transmitted to end user or made public. The proposed algorithm is used to insert a binary watermark image into a detailed coefficient of the Daubechies 9/7-based DWT transform. A watermark is dispersed consistently in low frequencies, which builds the robustness and inaudibility of the watermark data. Further, the watermark is embedded into an audio signal to have robust system against audio attacks and inaudible performance. The algorithm is verified using MATLAB and subsequently implemented on FPGA hardware to verify the real-time performance. Hardware implementation helps to embed the watermark at the same instance when audio is being captured. The results show promising application for real-time audio applications