Research On Audio Watermark Resistant To MP3 Compression

With the arrival of global informatization, information technology has been widely and deeply applied in every walk of life. Meanwhile the problem of how to protect digital multimedia has become more and more important. Digital audio watermarking as a powerful technology of copyright protection of audio becomes a hot issue.However human auditory system (HAS) is more sensitive than the human visual system (HVS). Therefore audio watermark research is latter than image watermark and video watermark. Comparing with digital image and video watermark technologies, digital audio watermark technology faces greater challenges. Most of the audio file formats are MP3 format. MP3 coding is a kind of perception coding. It is get high sound quality because it made full use of the human auditory system features and psychoacoustical model. After MP3 data compression, the redundant data in the compressed audio is less than ever before.So it has become more difficult to embed watermarks in compressed audio files.This paper do a research base MP3 coding theory and human auditory system, to find a algorithm of extracting watermarking from audio file after MP3 compressed. The embedding procedure is performed with MP3 encoding simultaneously Psychoacoustical model is used to search suitable location in low quantized modify discrete cosine transformation (QMDCT) coefficient adaptively. The noise which is produced by data embedding will be controlled within allowed distortion by outer iteration loop of MP3 encoding. The experimental results show that comparing to the famous information hiding software MP3Stego, the proposed algorithm can obtain higher hidden data capacity. The watermark is undetectable by human hearing and can against MP3 compression of different bit rate.The innovation of the algorithm is that it proposes a watermarking scheme combined Psychoacoustical model and MP3 coding processing for MP3 files'copyright.To improve the robustness of the algorithm, we introduce the BCH error correction code of the communication model into the watermark system. The new watermark system with error correction code has less watermark capacity than watermark system without error correction code. But the new system with error correction code gets a better robustness after MP3 compression.