FINGERPRINTING MULTIMEDIA CONTENTS

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.