A study on sound quality and embedding capacity of time-spread echo method for digital audio watermarking

摘要

Several methods for digital audio watermarking have been proposed, such as echo hiding, spread spectrum, masking, and phase modulation. Among these methods, echo hiding provides many advantages. However, there is a weak with this method from view point from protecting copyrights, because its decoding process is very lenient. To cope with this weak point of the echo hiding, we proposed a time-spread echo method using PN sequences that play a role of a secret key in decoding the embedded information. In this paper, we investigate the embedding capacity, the robustness against typical signal transformations, and the sound quality of the proposed method.