| 摘要 |
Disclosed is a method and arrangement for extracting a fingerprint from a multimedia signal, particularly an audio signal, which is invariant to speed changes of the audio signal. To this end, the method comprises extracting ( 12,13 ) a set of robust perceptual features from the multimedia signal, for example, the power spectrum of the audio signal. A Fourier-Mellin transform ( 15 ) converts the power spectrum into Fourier coefficients that undergo a phase change only if the audio playback speed changes. Their magnitudes or phase differences ( 16 ) constitute a speed change-invariant fingerprint. By a thresholding operation ( 19 ), the fingerprint can be represented by a compact number of bits.
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