Audio Data Spread Spectrum Embedding and Detection
AssigneeDolby Laboratories Licensing Corporation
InventorRegunathan Radhakrishnan
Life of this patent
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Abstract
An audio data spread spectrum embedding and detection method is presented. For each audio frame, a noise sequence is chosen according to the data to be embedded. Then, a spectrum of a chosen noise sequence is shaped by a spectrum of a current audio frame and subtracted from a current frame's spectrum. During detection, a detector is used on a watermarked audio frame to first whiten the watermarked audio frame. Detection scores are then computed against two competing Adaboost learning models. A detected bit is chosen according to the model with a maximum detection score.
Claims23
A method to embed data in an audio signal, comprising:
- selecting a pseudo-random sequence according to desired data to be embedded in the audio signal;
- shaping a frequency spectrum of the pseudo-random sequence with a frequency spectrum of the audio signal, thus forming a shaped frequency spectrum of the pseudo-random noise sequence;
- and
- subtracting the shaped frequency spectrum of the pseudo-random sequence from the frequency spectrum of the audio signal spectrum.
A computer-readable storage medium having stored thereon computer-executable instructions executable by a processor to detect embedded data in an audio signal, the detecting comprising:
- calculating detection scores from a set of competing statistical learning models, wherein the detection scores are based on the audio signal;
- and
- performing a detection decision as to which data is embedded in the audio signal by comparing with each other the calculated detection scores.
A system to embed data in an audio signal, the system comprising:
- a processor configured to:
- select a pseudo-random sequence according to desired data to be embedded in the audio signal;
- shape a frequency spectrum of the pseudo-random sequence with a frequency spectrum of the audio signal, thus forming a shaped frequency spectrum of the pseudo-random sequence;
- and
- subtract the shaped frequency spectrum of the pseudo-random noise sequence from the frequency spectrum of the audio signal spectrum.
A system to detect embedded data in an audio signal, the system comprising:
- a processor configured to:
- calculating detection scores from a set of competing statistical learning models, wherein the detection scores are based on the audio signal;
- and
- performing a detection decision as to which data is embedded in the audio signal by comparing a first model score for detecting a zero bit with a second model score for detecting a one bit.
Dependencies are inferred from the claim text.