Audio Watermarking based on Quantization Index Modulation in the Frequency Domain

In this paper, our main purpose is to embed data in the frequency domain of audio signals. Data was embedded by means of quantization index modulation (QIM) in the frequency domain. With this aim, the spectrum of the audio signal was divided into two parts. The first part consisted of the first 19 Barks and the second included the remaining 6 Barks. Each of these parts had a different quantization step size. In order to have large quantization step sizes which yield more robustness, Human Auditory System (HAS) has been used. Decoder detects the watermark signal, without using the original audio signal. Simulation results have shown that this watermarking scheme has better robustness against some common attacks, such as white Gaussian noise, echo, filtering, and MP3 compression, than similar approaches in the time and wavelet domains with the same computational complexity.