Audio Watermarking Based on Amplitude Variation to Enhance Imperceptibility and Robustness of an Audio Signal

In recent years, proliferation of digital multimedia including images, audio, video and documents become popular due to on line distribution of digital multimedia. In such an open environment, it is convenient to get the access to various information sources. This increases the possibility of large-scale unauthorized copying of digital data. These concerns over protecting copyright have triggered significant research to find ways to hide copyright messages and serial number into digital media. In this paper, to enhance imperceptibility and robustness of an audio signal, we propose a robust audio watermarking technique based on pseudo-random gray sequences that embed multi bits within an audio signal. Proposed audio watermarking algorithm aims to satisfy and maximize both imperceptibility and robustness of the watermark by embedding 1023 bits within a sample of an audio signal. Proposed technique relies on basic principle that on varying the amplitude of the host signal by a few percent produces inaudible variations resulting in a watermarked signal which sounds identical to the original host file. The imperceptibility and the robustness of watermarking based on amplitude variation of host signal according to PN gray sequence is tested using various attacks.