Multiple transform utilization and application for secure digital watermarking
First Claim
1. A method for protecting a digital signal, comprising:
- obtaining a digital signal comprising a plurality of digital blocks;
transforming, using a processor, each of the digital blocks into the frequency domain using a spectral transform;
identifying a plurality of frequencies and associated amplitudes for each set of the transformed digital blocks;
selecting a subset of the identified amplitudes based on the survivability of message information against signal manipulation;
choosing said subset of the identified amplitudes for each of the digital blocks using a primary mask from a key;
choosing message information using a transformation table generated with a convolution mask; and
,encoding, using a processor, the chosen message information into said transformed digital blocks by altering the selected amplitudes based on the chosen message information.
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Abstract
Multiple transform utilization and applications for secure digital watermarking. In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
391 Citations
24 Claims
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1. A method for protecting a digital signal, comprising:
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obtaining a digital signal comprising a plurality of digital blocks; transforming, using a processor, each of the digital blocks into the frequency domain using a spectral transform; identifying a plurality of frequencies and associated amplitudes for each set of the transformed digital blocks; selecting a subset of the identified amplitudes based on the survivability of message information against signal manipulation; choosing said subset of the identified amplitudes for each of the digital blocks using a primary mask from a key; choosing message information using a transformation table generated with a convolution mask; and
,encoding, using a processor, the chosen message information into said transformed digital blocks by altering the selected amplitudes based on the chosen message information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification