An Adaptive Watermarking Algorithm for MP3 Compressed Audio Signals

MP3 has been generating a significant popularity for distributing digital audio signals over the Internet. However, copyright issue has been raised because of illegal copy and redistribution. Digital watermarking is a technology that allows users to embed watermark into digital contents to identify the copyright holder, to prevent illegal copy, and to verily modification to the original content. This paper proposes a novel adaptive watermarking algorithm for MP3 compressed audio signals, based on human auditory system. In the proposed algorithm, watermark is embedded adaptively and transparently after modified discrete cosine transformation (MDCT) and before quantization. Gaussian distribution statistic analysis is introduced to make this watermarking algorithm adaptive. We tested our adaptive watermarking algorithm on various types of audio signals. The experimental results show that the new algorithm can survive most common signal manipulation including MP3 compression.