| 摘要 |
PROBLEM TO BE SOLVED: To prevent a relative phase relation from being considerably different from that of a source signal and being sensed as distortion in the axial direction of frequency in a phase changing method. SOLUTION: When the phase of a music signal is modulated in the manner of sine wave by using a secondary full band pass filter and the cycle of modulation if <= hundreds of Hz, it is not sensed by a human being. An electronic watermark is provided by embedding a watermark information with such phase modulation as a carrier. On a detection side, the model of the full band pass filter used for phase modulation is known. Therefore, the filter is estimated by ARMA model parameter estimation and the moving characteristics of the phase modulation are estimated from the change thereof with time. |
