DIGITAL WATERMARK DETECTION DEVICE AND DIGITAL WATERMARK DETECTION METHOD, AS WELL AS TAMPERING DETECTION DEVICE USING DIGITAL WATERMARK AND TAMPERING DETECTION METHOD USING DIGITAL WATERMARK

摘要

A digital watermark detection device is provided with a first chirp z-transformer (202a) and a second chirp z-transformer (202b) for estimating a cochlear delay characteristic simulated by a cochlear delay filter used when embedding digital watermark data in an acoustic signal, and the digital watermark detection device detects the digital watermark data embedded in the acoustic signal on the basis of the cochlear delay characteristic estimated through the results of the chirp z-transform by the first chirp z-transformer (202a) and the second chirp z-transformer (202b).