Fast and Low-Complexity Audio Watermarking

This article presents a fast and low complexity audio watermarking system which is very suitable for mobile device applications. The key idea is to divide the FFT spectrum into short frames and change the magnitude of the selected FFT samples using Fibonacci numbers. The suggested technique guarantees and proves, mathematically, that the maximum change is less than 61% of the related FFT sample and the average error for each sample is 25%. Using the closest Fibonacci number to FFT magnitudes results in a robust and transparent technique. On top of very remarkable capacity, transparency and robustness, this scheme provides two parameters which facilitate the regulation of these properties. The experimental results show that the method has a high capacity (700 to 3 kbps), without significant perceptual distortion (ODG is about - 1) and provides robustness against common audio signal processing such as echo, added noise, filtering and MPEG compression (MP3). In addition to the experimental results the fidelity of suggested system is proved mathematically.