A Blind Audio Watermarking Scheme Employing DCT–HT–SD Technique

Abstract

In this paper, a blind audio watermarking technique using discrete cosine transform (DCT), Hadamard transform (HT) and Schur decomposition (SD) is presented. The embedding of watermark is carried out by modifying the DCT coefficients through HT and SD. Watermark is embedded in the selected high-energy low-frequency frames of audio signal. The watermark bits are adaptively embedded in the unitary matrix obtained from SD. To make the proposed watermarking technique fully blind, embedding of watermark is performed by effectively utilizing the ratio between the first column elements of unitary matrix. Experimental results confirm that the proposed technique is robust to various signal processing attacks, such as re-sampling, re-quantization, noise addition, filtering, scaling and compression. The comparison of payload and robustness reveals that the proposed watermarking technique outperforms the existing techniques.