| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for embedding information into a sound signal that can increase the amount of information to be embedded and precision of extraction by improving the probability to embed data and also eliminate bit inversion even if a slight shift is caused by improving precision of shift correction. SOLUTION: A plurality of window functions are prepared and a sound signal is read in sound frame units of specified size; and each sound frame is frequency-converted by using the plurality of window functions and after the relation between low-frequency components of the front part and rear part of a sound frame is changed according to a binary value of a bit series to be embedded, the low-frequency components are synthesized with high-frequency components. At this time, a "0" embedding function and a "1" embedding function are made asymmetrical with each other and then bits are not inverted so as not to be recognized on an extraction side to improve the extraction precision of embedded information. COPYRIGHT: (C)2007,JPO&INPIT
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