| 摘要 |
PROBLEM TO BE SOLVED: To make noise caused by inserting a watermark less conspicuous. SOLUTION: In the watermark insertion method, a watermark inserting position is randomly determined with respect to musical sound signals. If one of the binary watermark information is '1', the musical sounds from an insertion position Pn to Xmsec are duplicated and made into as insertion signals. If the information is '0', the musical sounds from Pn+X to Xmsec are duplicated and inserted to an insertion position Pn as insertion signals. Note that before inserting the signals, the musical sounds from the position Pn to Xmsec are duplicated, the sound pressure is increased for 5 dB to produce relative signals, the signals are delayed for Ymsec, that is an allowable delay for the perception characteristic, and the signals are inserted into the musical sounds. Thus, the insertion signals are suppressed hearingwise by the relative signals. |
