Today I read a paper titled “Robust Audio Watermarking Against the D/A and A/D conversions”
The abstract is:
Audio watermarking has played an important role in multimedia security.
In many applications using audio watermarking, D/A and A/D conversions (denoted by DA/AD in this paper) are often involved.
In previous works, however, the robustness issue of audio watermarking against the DA/AD conversions has not drawn sufficient attention yet.
In our extensive investigation, it has been found that the degradation of a watermarked audio signal caused by the DA/AD conversions manifests itself mainly in terms of wave magnitude distortion and linear temporal scaling, making the watermark extraction failed.
Accordingly, a DWT-based audio watermarking algorithm robust against the DA/AD conversions is proposed in this paper.
To resist the magnitude distortion, the relative energy relationships among different groups of the DWT coefficients in the low-frequency sub-band are utilized in watermark embedding by adaptively controlling the embedding strength.
Furthermore, the resynchronization is designed to cope with the linear temporal scaling.
The time-frequency localization characteristics of DWT are exploited to save the computational load in the resynchronization.
Consequently, the proposed audio watermarking algorithm is robust against the DA/AD conversions, other common audio processing manipulations, and the attacks in StirMark Benchmark for Audio, which has been verified by experiments.