Audio data hiding based on perceptual masking and detection based on code multiplexing

摘要

A spread spectrum data hiding for audio signals is described. A set of pseudo-random noise sequences is added to an audio signal according to a data to be embedded. A masking curve is used to shape the added noise. A transient detection step can be used to control whether a shaped noise sequence is to be added or not. Embedded information is detected by first performing a whitening step and then performing a phase-only correlation with a same set of pseudo-random noise sequences. A detection method that is based on correlation of multiplexed noise sequences with a noise sequence embedded in the audio is also described.

主权项

1. A computer-implemented method to embed data in an audio signal, comprising:
selecting a pseudo-random sequence according to desired data bits to be embedded in the audio frame; computing, by a processor, a masking curve based on the audio signal; shaping a frequency spectrum of the pseudo-random sequence in accordance with the masking curve, thus obtaining a shaped frequency spectrum of the pseudo-random noise sequence; detecting, for audio signal frames, presence or absence of transients; and adding, by a processor, the shaped frequency spectrum of the pseudo-random noise sequence to a frequency spectrum of the audio signal, the adding occurring on an audio signal frame by audio signal frame basis, wherein, for audio signal frames for which presence of a transient is detected, the shaped frequency spectrum of the pseudo-random noise sequence is not added to the frequency spectrum of the audio signal.