Abstract: A tangible medium having a machine-readable symbol printed thereon, such that the symbol encodes a specified digital value in a set of color elements having different, respective colors, to be identified in an image of the symbol as red, green, blue, cyan, magenta and yellow color elements, respectively. The symbol is produced by applying cyan, magenta and yellow pigments to a substrate so as to produce the color elements, such that the color elements exhibit certain red, green, and blue intensity characteristics when measured in an sRGB color space.

Abstract: A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

Abstract: Adaptive spectacles (20) include a spectacle frame (25) and first and second electrically-tunable lenses (22, 24), mounted in the spectacle frame. In one embodiment, control circuitry (26) is configured to receive an input indicative of a distance from an eye of a person wearing the spectacles to an object (34) viewed by the person, and to tune the first and second lenses in response to the input.

Abstract: An optical device includes an electro-optical layer, having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. An array of excitation electrodes, including parallel conductive stripes extending over the active area is disposed over one or both sides of the electro-optical layer. Control circuitry is coupled to apply respective control voltage waveforms to the excitation electrodes and is configured to concurrently modify the respective control voltage waveforms applied to excitation electrodes so as to generate a specified phase modulation profile in the electro-optical layer.

Abstract: A method for distributing information includes producing a symbol to be overlaid on at least one primary image presented on a first display screen, the symbol encoding a specified digital value in a set of color elements having different, respective colors. A message is received from a client device containing an indication of the specified digital value decoded by the client device upon capturing and analyzing a secondary image of the first display screen. In response to the message, an item of information relating to the primary image is transmitted to the client device, for presentation on a second display screen associated with the client device.

Abstract: A method for distributing information includes producing a symbol (26, 64, 72, 74, 76, 78, 80, 90) to be overlaid on at least one primary image presented on a first display screen (24, 62) the symbol encoding a specified digital value in a set of color elements (28, 82, 92) having different, respective colors. A message is received from a client device (32, 68) containing an indication of the specified digital value decoded by the client device upon capturing and analyzing a secondary image of the first display screen. In response to the message, an item of information (50, 70) relating to the primary image is transmitted to the client device, for presentation on a second display screen (34) associated with the client device.

Abstract: An optical device includes an electro-optical layer, having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. An array of excitation electrodes, including parallel conductive stripes extending over the active area is disposed over one or both sides of the electro-optical layer. Control circuitry is coupled to apply respective control voltage waveforms to the excitation electrodes and is configured to concurrently modify the respective control voltage waveforms applied to excitation electrodes so as to generate a specified phase modulation profile in the electro-optical layer.

Abstract: An optical device (24, 60) includes an electro-optical layer (40, 62), having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. An array of excitation electrodes (46, 68, 72), including parallel conductive stripes extending over the active area is disposed over one or both sides of the electro-optical layer. Control circuitry (48, 70, 74) is coupled to apply respective control voltage waveforms to the excitation electrodes and is configured to concurrently modify the respective control voltage waveforms applied to excitation electrodes so as to generate a specified phase modulation profile in the electro-optical layer.

Abstract: A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

Abstract: A method for information display includes specifying information pertaining to a target location and encoding the specified information in a machine-readable symbol (22, 60) comprising a set of three or more color elements (40), which have different, respective colors that encode a first part of the information and are contained within a non-rectangular border (44), which has a shape characteristic that encodes a second part of the information. The symbol is positioned in the target location.

Abstract: A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

Abstract: Adaptive spectacles (20) include a spectacle frame (25) and first and second electrically-tunable lenses (22, 24), mounted in the spectacle frame. In one embodiment, control circuitry (26) is configured to receive an input indicative of a distance from an eye of a person wearing the spectacles to an object (34) viewed by the person, and to tune the first and second lenses in response to the input.

Abstract: An optical device (34, 66, 76) includes an electro-optical layer (48), having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. Conductive electrodes (44, 64, 74, 82, 84) extend over opposing first and second sides of the electro-optical layer. The electrodes include an array of excitation electrodes, which extend along respective, mutually-parallel axes in a predefined direction across the first side of the electro-optical layer, and which includes at least first and second electrodes having different, respective widths in a transverse direction, perpendicular to the axes. Control circuitry (38) is coupled to apply respective control voltage waveforms to the excitation electrodes so as to generate a specified phase modulation profile in the electro-optical layer.

Abstract: A method for distributing information includes producing a symbol (26, 64, 72, 74, 76, 78, 80, 90) to be overlaid on at least one primary image presented on a first display screen (24, 62) the symbol encoding a specified digital value in a set of color elements (28, 82, 92) having different, respective colors. A message is received from a client device (32, 68) containing an indication of the specified digital value decoded by the client device upon capturing and analyzing a secondary image of the first display screen. In response to the message, an item of information (50, 70) relating to the primary image is transmitted to the client device, for presentation on a second display screen (34) associated with the client device.

Abstract: A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

Abstract: A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

Abstract: An optical device (24, 60) includes an electro-optical layer (40, 62), having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. An array of excitation electrodes (46, 68, 72), including parallel conductive stripes extending over the active area is disposed over one or both sides of the electro-optical layer. Control circuitry (48, 70, 74) is coupled to apply respective control voltage waveforms to the excitation electrodes and is configured to concurrently modify the respective control voltage waveforms applied to excitation electrodes so as to generate a specified phase modulation profile in the electro-optical layer.

Abstract: Imaging apparatus includes an image sensor, which is adapted to generate an input image in response to optical radiation. A processing engine is configured to apply a digital filter, having a kernel width greater than five pixels, to the input image to generate a filtered image. An optical assembly is arranged to focus the optical radiation onto the image sensor with a point spread function such that no more than a first threshold percentage of energy emitted from a point object and focused by the optical assembly falls within a first region of the image sensor having a first width five times the pitch of the image sensor, while at least a second threshold percentage of the energy emitted from the point object and focused by the optical assembly falls within a second region, which contains the first region and has a second width corresponding to the kernel width.

Abstract: A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

Abstract: An optical imaging assembly having cylindrical symmetry, comprising a plurality of lenses having surfaces with curvatures and spacings between the surfaces, such that an optical image formed by the plurality of lenses has a defocus aberration coefficient greater than 0.1 at a focal plane of the assembly.