AUTHENTICITY OF AUDIO SIGNAL USING WATERMARKING TECHNIQUES

Audio watermarking provides a means to transmit codes within the audio signal which can be used in copy-protection schemes to prove ownership. The basic idea of embedding watermarks into audio signals is to hide a noise-like signal, which carries the watermark information, below the signal's masking threshold ­ thus ensuring its inaudibility. Watermark embedding into audio signals can be done either before compression for distribution (PCM watermarking) or after compression (bit stream watermarking). There are two important issues that audio watermarking algorithms need to address. Firstly, watermarking schemes are required to provide trustworthy evidence for protecting rightful ownership. Secondly, good watermarking schemes should satisfy the requirement of robustness and resist distortions due to common manipulations (such as truncation, compression etc.). In this paper, we have added logo image in audio signal. Audio watermarking approaches performed in the Time domain and Discrete Cosine Domain. The technique takes advantage of the invariant features of the Discrete Cosine Transform (DCT) and the Robustness capability of Arnold transform to improve the overall performance of audio watermarking. Besides, an image-watermarked audio signal does not exhibit noticeable audible distortion. A blind watermark detection technique is developed to isolate the embedded watermark even under distorted reception of the signal.