Real-Time Audio Watermarking

Abstract

ABSTRACT: A real-time audio watermarking scheme is proposed in which the strength of the watermark, embedded into the audio signal is limited to produce a watermarked signal perceptually closely similar to the original one. The proposed scheme uses a spread spectrum approach to embed the watermark which is generated by using a private key, and a blind detection algorithm to extract the watermark from the watermarked audio signal. Real-time implementaciуn of proposed scheme is also given which only requires 70 MIPS. Evaluation results show that the embedded watermark is robust to common attacks such like D/A and A/D conversions, filtering, noise addition and high quality MPEG audio coding. Subjective and objective evaluation results are also given to show the quality of watermarked signal. INTRODUCTION The quickly growth of the internet has increased the availability of a large amount of data, images, audio and video, doing it easy the unauthorized reproduction and manipulation of these multimedia materials. Thus the development efficient methods to protect the intellectual property of multimedia materials, as well as to detect unauthorized manipulation have become an urgent necessity. One of the possible solutions to these problems is so called watermark technology, in which an imperceptible and statistically undetectable signature is embedded to the multimedia material. A watermark completely characterizes the copyright owner and then it could be used to prove the intellectually property if only the owner of the multimedia material can detect the watermark. However to be suitable for using in practical applications, a watermark system should satisfy several requirements: firstly the watermark must be statistically undetectable. Second, it also must be robust to several signal processing algorithms such that the watermark can not be destroyed when the signal goes through several kinds of signal processing tasks such as: filtering, compression, change on the sampling, noise corruption, etc. Finally the watermark must be imperceptible to preserve the original signal quality. 327