A digital watermarking for audio data using band division based on QMF bank

In the watermarking techniques for audio are required quality, security and robustness. This paper presents method that improves security and robustness, besides restricting the noise. Special attention is given to band-division by using filter bank based on the QMF that several audio compression standards adopt. First, divides time-domain data into several subbands and select the sub band to embed the watermarking. Then, we spread the signal included in the selected sub band using Direct Spectrum Spreading(DSS) that is the one of the spectrum spreading methods, and embed the watermarking in the frequency-domain data. Finally, we reconstruct the signal by synthesizing whole subbands. By this method, we can reduce the noise and improve security and robustness against MPEG1 Audio Layer3 compression. Experimental results will show good robustness of the approach against some signal processing manipulations. Quality and robustness are evaluated by computer simulation.