Digital watermarking method and apparatus for audio data
First Claim
1. A method for inserting a watermark signal into audio signal data, comprising the steps of:
- Fourier transforming audio signal data in the frequency domain in a form of first components and second components;
wavelet transforming absolute values of said first components to generate first spectral coefficients;
discrete cosine transforming a watermark signal to generate second spectral coefficients;
combining said first spectral coefficients and said second spectral coefficients; and
inverse wavelet transforming the combined coefficients.
1 Assignment
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Accused Products
Abstract
Digital watermarking of digital audio is performed by Fourier transforming digital audio data, wavelet transforming the magnitude components of the Fourier transform coefficients of the digital audio data, discrete cosine transforming a watermark signal, multiplying the sign of the wavelet transform coefficients of the magnitude components to the coefficients of the discrete cosine transformed watermark signal, adding the coefficients of the Fourier transformed digital audio data and the adjusted discrete cosine transformed watermark signal, and inverse wavelet transforming the audio signal'"'"'s coefficients before inverse Fourier transformation to finally generate watermark-embedded audio signal data.
110 Citations
24 Claims
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1. A method for inserting a watermark signal into audio signal data, comprising the steps of:
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Fourier transforming audio signal data in the frequency domain in a form of first components and second components;
wavelet transforming absolute values of said first components to generate first spectral coefficients;
discrete cosine transforming a watermark signal to generate second spectral coefficients;
combining said first spectral coefficients and said second spectral coefficients; and
inverse wavelet transforming the combined coefficients. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for inserting a watermark signal into audio signal data, comprising:
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a means for Fourier transforming audio signal data into amplitude components and phase components;
a means for wavelet transforming absolute values of said amplitude components to generate first spectral coefficients;
a means for discrete cosine transforming a watermark signal to generate second spectral coefficients;
a means for combining said second spectral coefficients to said first spectral coefficients respectively; and
inverse wavelet transforming the coefficients. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method for extracting a watermark from a watermark-embedded audio data, comprising steps of:
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Fourier transforming a watermark-embedded audio data and an original audio data to generate first components and second components respectively;
Wavelet transforming the absolute magnitudes of said first components of said watermark-embedded audio data and said original audio data respectively;
taking the differences between wavelet-transform coefficients of said watermark-embedded audio data and said original audio data; and
inverse-discrete cosine transforming said differences. - View Dependent Claims (16, 17, 18, 19)
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20. An apparatus for extracting a watermark from a watermark-embedded audio data, comprising:
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a means for Fourier transforming a watermark-embedded audio data and an original audio data to generate first components and second components respectively;
a means for wavelet transforming the absolute magnitudes of said first components of said watermark-embedded audio data and said original audio data respectively;
a means for taking the differences between wavelet-transform coefficients of said watermark-embedded audio data and said original audio data; and
a means for inverse-discrete cosine transforming said differences. - View Dependent Claims (21, 22, 23, 24)
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Specification