Digital Audio Watermarking Based on Time-Spread Echo Hiding

摘要

Recently, digital watermarking techniques has received much attention for copyright protection of digital media contents. In this study, a novel digital watermarking technique for copyright protection for digital audio contents is proposed by spreading the echo of conventional echo hiding using pseudo-noise (PN) sequences to cope with the weak point of conventional echo hiding. The robust embedding for the proposed method is also proposed by decomposing a host signal into multiple-subband signals and controlling the amplitude of the PN sequence for each subband as a function of the masking level. To enhance the robustness against pitch-scaling, a log-scaling method is proposed by using the logarithm operation. Evaluations for the proposed techniques are carried out via computer simulations.