| 摘要 |
A system and method of retrieving a watermark in a watermarked signal are disclosed. The watermarked signal comprises odd and even overlapped blocks where the watermark is contained in the even blocks. The method comprises, for each k-th even block, subtracting the two adjacent odd numbered blocks from the k-th even block of the watermarked signal to retrieve s *k(n), transforming s *k(n) into the frequency domain to generate S k(f), calculating a phase of S k(f) asφ(f) and a phase of Sk(f) asφ(f), calculating the differenceΨ(f) betweenφ(f) andφ(f), unwrappingΨ(f) to obtain the phase modulation {tilde over (Φ)} k(f), and using a Viterbi search to retrieve the watermark embedded in {tilde over (Φ)} k(f).
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