Multiple transform utilization and application for secure digital watermarking
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.
1 - 60 . (canceled)
61 . A method of building a database for authenticating content encoded with a message, in which an encoding process employs at least one transform function, a primary mask, and a convolution mask, comprising:
storing in non transient memory in association with one another, the following: a first identification of at least one transform function that transforms from time or space to temporal or spatial frequency, a first primary mask, a first convolution mask, first data corresponding to a first message, a first reference subset of pixels, and first original dimensions, wherein said first reference subset of pixels are a subset of pixels from a first original content, wherein said first original dimensions are original dimensions of said first original content;
encoding, using a processor, said first original content with said first message, with an encoding process using said at least one transform function, said first primary mask, said first convolution mask, and said first message;
storing in said non transient memory in association with one another, the following: a second identification of at least one transform function that transforms from time or space to temporal or spatial frequency, a second primary mask, a second convolution mask, second data corresponding to a second message, a second reference subset of pixels, and second original dimensions, wherein said second reference subset of pixels are a subset of pixels from a second original content, wherein said second original dimensions are original dimensions of said second original content; and
encoding, using a processor, said second original content with said second message, with an encoding process using said at least one transform function, said second primary mask, said second convolution mask, and said second message.
62 . A system comprising a database for authenticating content encoded with a message in which an encoding process employed at least one transform function, a primary mask, and a convolution mask, comprising:
a processor;
memory for storing data in non transient form;
wherein said memory stores in association with one another, the following: a first identification of at least one transform function that transforms from time or space to temporal or spatial frequency, a first primary mask, a first convolution mask, first data corresponding to a first message, a first reference subset of pixels, and first original dimensions, wherein said first reference subset of pixels are a subset of pixels from a first original content, wherein said first original dimensions are original dimensions of said first original content;
wherein said memory stores in association with one another, the following: a second identification of at least one transform function that transforms from time or space to temporal or spatial frequency, a second primary mask, a second convolution mask, second data corresponding to a second message, a second reference subset of pixels, and second original dimensions, wherein said second reference subset of pixels are a subset of pixels from a second original content, wherein said second original dimensions are original dimensions of said second original content; and
an authenticator for determining if a content is authentic by applying a decode algorithm thereto, wherein said decode algorithm uses an associated set of datum stored in said memory, comprising: a transform function, a primary mask, a convolution mask, a message, a reference subset of pixels, and original dimensions, wherein said authenticator determines said content to be authentic if said content contains the message contained in said associated set.