Modified Phase Coding Audio Watermarking Resistant to Signal Attacks

In this paper, a new phase coding method is usedto embed any watermark data type (text, image, audio) in audio signals. The basic idea is to segment the audio signal and transformingitusing the Discrete Fourier Transformation(DFT) and then embedding the watermark in the initial phase coefficientsfor every four segments. The used cover audio files of WAV type. The watermark can be extracted semi-blindly.Performance of the proposed watermarking methods was tested by using normalized correlation (NC) and bit error rates (BER) to measure the robustness, and signal to noise ratio (SNR) to evaluate the imperceptibility of our proposed methods. Experimental results shows superiority of the proposed scheme in term of robustness, inaudibility and capacity compared within the traditional phase coding method, the best audio test sample shows that the SNR value was above (20 dB) for (250 byte) watermark capacity with high robustness against cropping attack and showed modest robustness against some type of attacks .