| 摘要 |
PROBLEM TO BE SOLVED: To provide an information embedding device to an acoustic signal and an information extracting device from the acoustic signal, capable of expanding a receivable distance area by using a frequency band which suppresses degradation of reproducing quality, and which spreads further in distance than before. SOLUTION: The acoustic signal is read by an acoustic frame unit of a predetermined size, and frequency conversion is performed by using a plurality of time direction windowing functions for each acoustic frame, and according to binary values of a bit sequence to be embedded, a state of a predetermined frequency band (1.7 to 3.4 kHz) is changed to " State 1" in which a front component strength is large, or "State 2" in which a rear component strength is large. At this time, in order to make the component strength large, the windowing function F which changes according to a value of a frequency direction so that the vale near a center of the predetermined frequency band may becomes large, is applied. COPYRIGHT: (C)2008,JPO&INPIT
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