Patent ID: 8620018

Claim:
A digital watermark detecting method for detecting a digital watermark that is embedded beforehand into an input signal having dimensions equal to or greater than N (N is an integer equal to or greater than 2) such that it is imperceptible to human senses in a digital watermark detection apparatus including demodulation means, detection sequence extraction means, correlation value calculation means, and storage means, the method comprising: measuring, at the demodulation means, a component of a predetermined periodic signal in a direction of a dimension in the input signal to obtain a Nâˆ’1-dimensional pattern; obtaining, at the detection sequence extraction means, a detection sequence from values of the Nâˆ’1-dimensional pattern and storing the detection sequence in the storage means; and detecting, at the correlation value calculation means, the embedded digital watermark based on a size of a correlation value between the detection sequence stored in the storage means and an embedding sequence.