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 includes a first chirp z-transform unit (202a) and a second chirp z-transform unit (202b) for estimating the cochlear delay characteristics simulated by cochlear delay filters that were used in embedding digital watermark data in an acoustic signal. The digital watermark data embedded in the acoustic signal is detected based on the cochlear delay characteristics estimated in accordance with the result of chirp z-transform applied by these first chirp z-transform unit (202a) and second chirp z-transform unit (202b).

主权项

1. A digital watermark detection device comprising:
a cochlear delay characteristics estimation means for estimating cochlear delay characteristics simulated by a cochlear delay filter in a case where a digital watermark data embedding device has embedded digital watermark data in an acoustic signal, which is digital data, the digital watermark data embedding device applying phase modulation to the acoustic signal using the cochlear delay filter that simulates the cochlear delay characteristics and embedding the digital watermark data in the acoustic signal to which phase modulation has been applied; and a digital watermark detection means for detecting the digital watermark data embedded in the acoustic signal based on the cochlear delay characteristics estimated by the cochlear delay characteristics estimation means.