Abstract: This invention relates to a device and a method of generating a first and a second fingerprint (102,104) usable for synchronisation of at least two signals (101,103) and corresponding method and device for synchronising two or more signals. A fingerprint pair is generated on the basis of a segment of a first signal e.g. an audio signal and of a segment of a second signal e.g. a video signal at each synchronisation time point. The generated fingerprint pair(s) are stored in a database (203) and communicated or distributed to a synchronisation device (303). During synchronisation, fingerprint(s) of the audio signal and fingerprint(s) of the video signal to be synchronised are generated and matched against fingerprints in the database. When a match is found, the fingerprints also determine the synchronisation time point, which is used to synchronise the two signals. In this way, a simple, reliable and efficient way of synchronising at least two signals is obtained.

Abstract: A graphics card of a computer system is configured to detect watermarks within a video signal that includes one or more windows of a display. The frames of the video signal are analyzed to locate image areas in which the video signal changes, and a bounding box around these areas of change is defined as an area(s) of interest. Watermark detection is then performed within the area(s) of interest.

Abstract: Hashes are short summaries or signatures of data files which can be used to identify the file. Hashing multimedia content (audio, video, images) is difficult because the hash of original content and processed (e.g. compressed) content may differ significantly. The disclosed method generates robust hashes for multimedia content, for example, audio clips. The audio clip is divided (12) into successive (preferably overlapping) frames. For each frame, the frequency spectrum is divided (15) into bands. A robust property of each band (e.g. energy) is computed (16) and represented (17) by a respective hash bit. An audio clip is thus represented by a concatenation of binary hash words, one for each frame. To identify a possibly compressed audio signal, a block of hash words derived therefrom is matched by a computer (20) with a large database (21). Such matching strategies are also disclosed.

Abstract: This invention relates to a method of embedding a watermark pattern with a payload in a time dependent information signal, comprising the steps of determining a number of robust signatures in the information signal, creating the payload being dependent of at least one of the number of robust signatures and a predefined message, embedding the watermark pattern according to the payload in the information signal. The invention also relates to a corresponding method and arrangement for detecting a watermark pattern in an information signal.

Abstract: An apparatus for content item signature matching comprises a database (103) which has signatures for a plurality of content items. A likelihood processor (105) determines a match likelihood indication for the content items where the match likelihood indication is indicative of a likelihood of a match between the content item and an unknown signature. An interface (111) receives a query signature associated with a content item and in response a search processor (113) searches the database (103) for a matching signature to the query signature. The search processor (113) is operable to search the database in response to the match likelihood indication of the plurality of content items. In particular the database (103) may be ordered in order of decreasing probability of a match and the search processor (113) may search the database in this order. Hence, the probability of an early match is increased and the average search time is reduced.

Abstract: The invention relates to a system for embedding auxiliary information in a media signal such as an audio visual signal. An apparatus comprises a quantization index modulator (103) which generates a modified signal by quantization index modulation of the media signal. The modified signal has distortions relative to the media signal which are dependent on the auxiliary information. The apparatus further comprises a perception processor (107) which generates a perceptual characteristic indicative of a perceptual sensitivity of the media signal to the distortions. The quantization index modulator (103) and perception processor (107) are coupled to a compensation processor (105) which generates an output signal by modifying a strength of the distortions of the modified signal in response to the perceptual characteristic. The invention combines quantization index modulation watermarking with perceptual models to provide an improved trade off between watermark imperceptibility and detection reliability.

Abstract: Hashes are short summaries or signatures of data files which can be used to identify the file. Hashing multimedia content (audio, video, images) is difficult because the hash of original content and processed (e.g. compressed) content may differ significantly. The disclosed method generates robust hashes for multimedia content, for example, audio clips. The audio clip is divided (12) into successive (preferably overlapping) frames. For each frame, the frequency spectrum is divided (15) into bands. A robust property of each band (e.g. energy) is computed (16) and represented (17) by a respective hash bit. An audio clip is thus represented by a concatenation of binary hash words, one for each frame. To identify a possibly compressed audio signal, a block of hash words derived therefrom is matched by a computer (20) with a large database (21). Such matching strategies are also disclosed.

Abstract: The invention relates to a method for use in a packet-switched communication system, the method comprising: sending a first packet from a source node to a destination node, the first packet containing a first set of data bits; sending a second packet from the source node to the destination node, the second packet containing a second set of data bits; wherein, in the event that the first set of data bits cannot be successfully decoded in the destination node, the second packet further comprises a first set of error correction bits for the first set of data bits.

Abstract: There is provided a method of detecting a watermark included in a signal by way of quantization index modulation (QIM). The signal with the embedded watermark may have been geometrically transformed (e.g. spatially or temporally scaled) prior to detection. In order to detect the watermark even in such case, the embedder imposes an autocorrelation structure onto the embedded watermark data, for example by tiling. Initially, the detector applies conventional QIM detection. This step yields a first symbol vector, which corresponds to the embedded data when the signal was not tampered with, but does not correspond to the embedded data when the signal was subject to scaling. For example, when one data bit is embedded in each pixel of an image, 50% upsampling of the image causes a QIM detector to retrieve 3 data bits out of 3 received pixels, that is 3 data bits out of 2 original image pixels. Surprisingly, the autocorrelation of the first symbol vector will give a peak for a particular geometric transformation (e.

Abstract: This invention relates to a device and a method of generating a first and a second fingerprint (102,104) usable for synchronisation of at least two signals (101,103) and corresponding method and device for synchronising two or more signals. A fingerprint pair is generated on the basis of a segment of a first signal e.g. an audio signal and of a segment of a second signal e.g. a video signal at each synchronisation time point. The generated fingerprint pair(s) are stored in a database (203) and communicated or distributed to a synchronisation device (303). During synchronisation, fingerprint(s) of the audio signal and fingerprint(s) of the video signal to be synchronised are generated and matched against fingerprints in the database. When a match is found, the fingerprints also determine the synchronisation time point, which is used to synchronise the two signals. In this way, a simple, reliable and efficient way of synchronising at least two signals is obtained.

Abstract: The invention relates to a method for generating a primary binary signal having a predetermined spectral shape in a predetermined frequency range, in particular having a notch in the power spectrum in a predetermined frequency range. In order to avoid crosstalk between a primary binary signal and a secondary binary signal it is proposed according to the invention that data-words are modulated into channel-words forming the channel bitstream of the primary binary signal and that the modulation of the data-words is chosen such that the predetermined spectral shape of the channel bitstream of the primary binary signal is achieved by using an evaluation criterion based on a spectral weight function the shape of which is tailored to the spectral extent of the channel bitstream of a secondary binary signal.

Abstract: A method and arrangement are disclosed for distributing multimedia content such that that the actual distribution of said content can be monitored in an efficient and reliable manner. The invention combines the extensiveness of feature extraction and the robustness of watermarking. Characteristic features of the content, e.g. luminance distribution, are extracted (11) to constitute a signature (SIG) of the content. In addition, a watermark is embedded (12) having a payload representing an index (ID) in a database (10) in which the content to be monitored is stored. The watermark serves as an index for limiting the database search needed for monitoring the signatures.

Abstract: An information system according to the invention comprises a record carrier and a playback apparatus. The record carrier has information marks along a track thereof and exhibits first variations caused by existence and nonexistence of the information marks along the track. The first variations represent an information signal recorded on said record carrier. The record carrier further exhibits second variations caused by variations associated with the information marks. The phase of the second variations is coupled to the phase of the first variations.

Abstract: A method and arrangement for detecting a watermark in a suspect signal, in which the watermark is embedded by adding a watermark pattern w to a signal p with a given embedding strength s (“additive embedding”: q=p+sw), includes correlating (2,3) it with the suspect signal. Recently, “multiplicative embedding” has been proposed (q=p(1+sw)). In this case, multiplicatively embedded watermarks are detected by raising (1) the signal to a power &bgr; prior to correlating it with the watermark. The power &bgr; may be fixed (e.g., &bgr;=2) or derived from a statistical analysis (5) of the signal.

Abstract: The invention relates to a method for generating a primary binary signal having a predetermined spectral shape in a predetermined frequency range, in particular having a notch in the power spectrum in a predetermined frequency range. In order to avoid crosstalk between a primary binary signal and a secondary binary signal it is proposed according to the invention that data-words are modulated into channel-words forming the channel bitstream of the primary binary signal and that the modulation of the data-words is chosen such that the predetermined spectral shape of the channel bitstream of the primary binary signal is achieved by using an evaluation criterion based on a spectral weight function the shape of which is tailored to the spectral extent of the channel bitstream of a secondary binary signal.

Abstract: The invention relates to a method for generating a primary binary signal having a predetermined spectral shape in a predetermined frequency range, in particular having a notch in the power spectrum in a predetermined frequency range. In order to avoid crosstalk between a primary binary signal and a secondary binary signal it is proposed according to the invention that data-words are modulated into channel-words forming the channel bitstream of the primary binary signal and that the modulation of the data-words is chosen such that the predetermined spectral shape of the channel bitstream of the primary binary signal is achieved by using an evaluation criterion based on a spectral weight function the shape of which is tailored to the spectral extent of the channel bitstream of a secondary binary signal.

Abstract: Hashes are short summaries or signatures of data files which can be used to identify the file. Hashing multimedia content (audio, video, images) is difficult because the hash of original content and processed (e.g. compressed) content may differ significantly.

Abstract: A method and arrangement are disclosed for distributing multimedia content such that that the actual distribution of said content can be monitored in an efficient and reliable manner. The invention combines the extensiveness of feature extraction and the robustness of watermarking. Characteristic features of the content, e.g. luminance distribution, are extracted (11) to constitute a signature (SIG) of the content. In addition, a watermark is embedded (12) having a payload representing an index (ID) in a database (10) in which the content to be monitored is stored. The watermark serves as an index for limiting the database search needed for monitoring the signatures.

Abstract: The invention relates to a method for generating a primary binary signal having a predetermined spectral shape in a predetermined frequency range, in particular having a notch in the power spectrum in a predetermined frequency range. In order to avoid crosstalk between a primary binary signal and a secondary binary signal it is proposed according to the invention that data-words are modulated into channel-words forming the channel bitstream of the primary binary signal and that the modulation of the data-words is chosen such that the predetermined spectral shape of the channel bitstream of the primary binary signal is achieved by using an evaluation criterion based on a spectral weight function the shape of which is tailored to the spectral extent of the channel bitstream of a secondary binary signal.

Abstract: A new and distinct cultivar of Hibiscus plant named ‘Sparkle’, characterized by its upright, somewhat, outwardly spreading and dense and bushy plant habit; dark green-colored leaves; freely flowering habit; large white-colored flowers with red purple-colored centers and venation; and good flower longevity.