Abstract: A method for inserting a digital signature into digital data is provided. The digital data has bits and the method includes the steps of: assigning predetermined bits of the digital data for receiving the digital signature; signing the digital data excluding the predetermined bits resulting in the digital signature; and inserting the digital signature into the predetermined bits of the digital data for subsequent authentication of the digital data.

Abstract: A system is described for linking traditional media works, such as print and broadcast media for example, to a more interactive media conduit, such as the Internet. The system avoids the need to modify the media work in anyway. Instead, it employs a passive recognition system that uniquely identifies the specific work, such as a particular television or radio broadcast or printed commercial. The identification may be based in intra-work and/or extra-work information. Several different embodiments/environments are described. The best embodiment may depend, at least in part, on costs of hardware and communication. These costs can change over time. In one embodiment, all of the databases and computation are performed at the user's premises. In another embodiment, all of the databases and computation occur at remote sites that user premise equipment can query using uniquely identifying extra-work information, such as the time, place and station on which the work was broadcast.

Abstract: A watermark message embedded in a cover work can be made robust to various types of post-embedding operations, while simultaneously minimizing perceptual impact on the cover work. This is accomplished by the informed coding of the watermark message to be embedded. This is also accomplished by the informed embedding of the watermark message code in the cover work. Finally, the watermark message code may be perceptually shaped to minimize impact on the fidelity of the watermarked work. Further, these techniques may be combined for maximum effect.

Abstract: A method for data preparation and watermark insertion. The method includes the step of preparing the data at a first time by manipulating at least one set of the data characteristics for subsequent insertion of a first watermark. In a preferred embodiment of the method of the present invention the method further includes the step of inserting the first watermark by manipulating the set of data characteristics at a second time subsequent to the first time. In still yet another preferred embodiment of the method of the present invention, the method further includes the step of inserting a second watermark at a third time, before, during, or after the first time, by manipulating at least one set of the data characteristics. In a variation of the present invention a method for inserting a watermark into compressed data is provided. The compressed data has sets of data characteristics.

Abstract: A cyclopean virtual imaging system provides a view from a virtual camera placed symmetrically or midway between the calibrated cameras of a physical stereo pair. Such a system may be used in video conferencing applications as well as other stereo image contexts. By combining the left and right stereo images captured by the stereo pair, a virtual image is produced such that the subject appears to be looking into a cyclopean virtual camera, rather than to the left or right of a single physical camera. The cyclopean virtual image is generated by a forward-backward algorithm using a probabilistic distribution of possible disparity families.

Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n×n blocks, such as the 8×8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8×8 blocks to form a set of N summed 8×8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain.

Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n×n blocks, such as the 8×8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8×8 blocks to form a set of N summed 8×8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain.

Abstract: A watermark message embedded in a cover work can be made robust to various types of post-embedding operations, while simultaneously minimizing perceptual impact on the cover work. This is accomplished by the informed coding of the watermark message to be embedded. This is also accomplished by the informed embedding of the watermark message code in the cover work. Finally, the watermark message code may be perceptually shaped to minimize impact on the fidelity of the watermarked work. Further, these techniques may be combined for maximum effect.

Abstract: Data is protected from unauthorized copying by rescrambling an unauthorized version of the data, but descrambling an authorized version of the data. This is done using a trigger signal. One property of the trigger signal is that it is preserved through signal transformations, such as one or more of compression, decompression, analog to digital conversion, and digital to analog conversion. As a result of this property the trigger signal can be detected in either scrambled or descrambled data. The trigger signal is embedded into the data to form watermarked data. The watermarked data is passed through a descrambler, where the trigger signal, if present, is extracted. A descrambling key and a descrambling algorithm are applied to the watermarked data if the trigger signal is present, but not applied to the watermarked data if the trigger signal is not present.

Abstract: A method for utilizing a title signal contained in data through a comparison of the title signal to a player signal stored in a player device is provided. Preferably, the data is digital image, video, or audio data. The method includes the steps of: providing data having the title signal; detecting, at the player device, the title signal in the data: comparing the title signal to the player signal stored at the player device; and performing an action based upon the comparison. In a preferred implementation, the action is performed if the title signal matches the player signal, and the action is to inform the device user of the match and the winning of a prize. In another preferred implementation, the title signal is a subsignal of a watermark signal encoded in the digital data, in which case the method further comprises the steps of: extracting the watermark signal from the digital data; and decoding the subsignal.

Abstract: A method for utilizing a title signal contained in digital data through a comparison of the title signal to a player signal stored in a player device. The method includes the steps of: downloading the digital data having the title signal via an Internet connection; possibly transferring the downloaded digital data to the player device; detecting, at the player device, the title signal in the data: comparing the title signal to the player signal stored at the player device; and performing an action based upon the comparison. In a preferred implementation of the present invention, the player device is a personal computer and the digital data is either image, video, audio or multimedia data or is an application program for running on the personal computer. Preferably, the player device is a personal computer. In other embodiments the title signal is contained in or part of an application program or is contained in data to be input into the application program.

Abstract: A system is described for linking traditional media works, such as print and broadcast media for example, to a more interactive media conduit, such as the Internet. The system avoids the need to modify the media work in anyway. Instead, it employs a passive recognition system that uniquely identifies the specific work, such as a particular television or radio broadcast or printed commercial. The identification may be based in intra-work and/or extra-work information. Several different embodiments/environments are described. The best embodiment may depend, at least in part, on costs of hardware and communication. These costs can change over time. In one embodiment, all of the databases and computation are performed at the user's premises. In another embodiment, all of the databases and computation occur at remote sites that user premise equipment can query using uniquely identifying extra-work information, such as the time, place and station on which the work was broadcast.

Abstract: A method for data preparation and watermark insertion. The method includes the step of preparing the data at a first time by manipulating at least one set of the data characteristics for subsequent insertion of a first watermark. In a preferred embodiment of the method of the present invention the method further includes the step of inserting the first watermark by manipulating the set of data characteristics at a second time subsequent to the first time. In still yet another preferred embodiment of the method of the present invention, the method further includes the step of inserting a second watermark at a third time, before, during, or after the first time, by manipulating at least one set of the data characteristics. In a variation of the present invention a method for inserting a watermark into compressed data is provided. The compressed data has sets of data characteristics.

Abstract: A method for data preparation and watermark insertion. The method includes the step of preparing the data at a first time by manipulating at least one set of the data characteristics for subsequent insertion of a first watermark. In a preferred embodiment of the method of the present invention the method further includes the step of inserting the first watermark by manipulating the set of data characteristics at a second time subsequent to the first time. In still yet another preferred embodiment of the method of the present invention, the method further includes the step of inserting a second watermark at a third time, before, during, or after the first time, by manipulating at least one set of the data characteristics. In a variation of the present invention a method for inserting a watermark into compressed data is provided. The compressed data has sets of data characteristics.

Abstract: A method for detecting a watermark signal in digital image data. The detecting method includes the steps of: computing a log-polar Fourier transform of the image data to obtain a log-polar Fourier spectrum; projecting the log-polar Fourier spectrum down to a lower dimensional space to obtain an extracted signal; comparing the extracted signal to a target watermark signal; and declaring the presence or absence of the target watermark signal in the image data based on the comparison. Also provided is a method for inserting a watermark signal in digital image data to obtain a watermarked image.

Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n×n blocks, such as the 8×8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8×8 blocks to form a set of N summed 8×8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain.

Abstract: Digital watermarking of audio, image, video or multimedia data is achieved by inserting the watermark into the perceptually significant components of a decomposition of the data in a manner so as to be visually imperceptible. In a preferred method, a frequency spectral image of the data, preferably a Fourier transform of the data, is obtained. A watermark is inserted into perceptually significant components of the frequency spectral image. The resultant watermarked spectral image is subjected to an inverse transform to produce watermarked data. The watermark is extracted from watermarked data by first comparing the watermarked data with the original data to obtain an extracted watermark. Then, the original watermark, original data and the extracted watermark are compared to generate a watermark which is analyzed for authenticity of the watermark.

Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n.times.n blocks, such as the 8.times.8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8.times.8 blocks to form a set of N summed 8.times.8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain.

Abstract: Detection of a watermark in blocks of video or image data which has been subjected to affine geometric distortion is accomplished by approximating the distortion by a spatially varying translation of the blocks. The watermark is extracted by spatial translations of the blocks based on an assumed affine geometric distortion. The extracted watermarks are correlated with possible watermarks and the maximum correlator output is tested for statistical significance in order to determine whether a watermark is present in the image or video frame. The data may be compressed or uncompressed data. If the affine geometric distortion is known, a search for the maximum correlator output over a space of possible distortions can be performed.

Abstract: Segmentation of an image into separate regions is useful in many computer vision problems. The separate regions may be represented by their enclosing contours. A planar graph is constructed for each image. The optimal contour is determined by the assignment of edge costs and face weights of the graph. An algorithm is provided such that given a planar graph G = (V,E) where V is a set of nodes, E is a set of edges and each edge e is provided with a non-negative cost c(e) and each face f of the planar graph is provided with a non-negative weight w(f), and given a single node v in G and single face F adjacent to v which is viewed as the exterior face, then find a directed path P in G that starts and finishes at v and minimizes ##EQU1## where cost(P) is defined as the length of the path under c, and weight (P) is the weight of the faces that are separated from F by P. The contour that minimizes .zeta. is the optimal contour.