Abstract: A method, device and arrangement insert extra information in an input signal in the acoustical or visual domain. A representation in the electrical domain is received, a watermark including the extra information is generated, and a watermark signal representing the watermark is output to the acoustical or visual domain. The watermark signal representing the watermark is merged with the input signal in the acoustical or visual domain. Any recording unit which attempts to record the input signal will automatically record the watermark signal as well, so no unwatermarked specimens are made available. The device may be realized as a computer program product, or as a small portable unit, which may be worn by a person to automatically watermark anything spoken. The device may be used to protect physical objects against unauthorized taking of photographs, by projecting a visual watermark signal towards the source or physical object.

Abstract: In a method and arrangement for embedding and detecting a watermark in an information signal, the embedded watermark (Wi) is selected (13) from a plurality of watermarks (W1 . . . WN) in dependence upon a property P of the signal. An example of such a property is the distribution of luminance values of the current video image as calculated by an analysis circuit (12). The corresponding watermark detector performs the same operation: the watermark being looked for depends on the same signal property. It is achieved with the invention that the embedded watermark changes from time to time as a function of the information signal content, so that it cannot easily be hacked.

Abstract: The display device (1) comprises picture elements (5) arranged in substantially parallel lines (6) on a display panel (2), and selection means (3) for controlling the decoupling of light from an optical waveguide plate at the picture elements. The selection means (3) are arranged for multiline addressing of the picture elements (5). For displaying gray scales, image information (4) is decomposed into a number of subfields (13) which are displayed. The time efficiency of the addressing of picture elements (5) in lines (16) in the subfields (13) is increased, enabling the display device (1) to display a relative large number of gray method of operating a display device (1) is carried out when the device is in operation.

Abstract: The invention relates to a method and a system (100) for embedding extra information in an input signal (101). Groups of one or more candidate frames in the input signal (101) are associated with respective portions of the extra information. Each group is edited in dependence on its associated respective portion, for example by deleting it to represent a zero bit in the respective portion and duplicating it to represent a one. The invention further relates to a method and system (200) for decoding extra information embedded in an input signal (201) by comparing it with an original input signal (204) and decoding the differences into the extra information. For example, missing groups of candidate frames are decoded into a zero bit, and duplicated candidate frames are decoded into a one bit.

Abstract: The invention relates to a method of embedding a watermark W in an information signal P, to a corresponding arrangement for embedding a watermark W in an information signal P, to an information signal P with an embedded watermark W and to a storage medium 50 having stored thereon an information signal P with an embedded watermark W. This method is carried out by determining local weight factors &lgr;(P) for said watermark based on data of said information signal P, wherein said local weight factors &lgr;(P) are determined such that the embedded watermark W is rendered substantially imperceptible when embedded in said information signal. The watermark W is locally weighted using said determined local weight factors &lgr;(P). Then said locally weighted watermark is embedded in said information signal P. When determining said local weight factors &lgr;(P) of said watermark W temporal data of said information signal are taken into account.

Abstract: Disclosed are a method, device (100) and arrangement for inserting extra information in an input signal (111) in the acoustical or visual domain. A representation in the electrical domain is received, a watermark comprising the extra information is generated and a watermark signal (113) representing the watermark is output to the acoustical or visual. There it merges with the input signal (111). Any recording unit (114) which attempts to record the input signal (111) will automatically record the watermark signal (113) as well, so no unwatermarked specimens are made available. The device (100) can be realized as a computer program product, or as a small portable unit, which can be worn by a person to automatically watermark anything he says. The device (100) can be used to protect physical objects against unauthorized taking of photographs, by projecting a visual watermark signal towards the source.