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: An information system according to the invention comprises a record carrier (1) and a playback apparatus (20). The record carrier has information marks along a track (11) 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 (W) caused by variations associated with the information marks. The phase of the second variations is coupled to the phase of the first variations.

Abstract: Disclosed is a method and arrangement for detecting a watermark in a suspect signal. Usually, a watermark is embedded by adding a watermark pattern w to a signal p with a given embedding strength s (“additive embedding”: q=p+sw). The embedded watermark is then detected by correlating (2,3) it with the suspect signal. Recently, “multiplicative embedding” has been proposed (q=p(1+sw)). In accordance with the invention, 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.