Abstract: A method for presenting information includes receiving a specified digital value for display, assigning to a set of colors respective digital codes comprising respective binary values representing three primary color components of the colors, and encoding the specified digital value by combining at least four of the digital codes while selecting the colors such that none of the binary values is constant over all of the selected colors. A symbol is presented for imaging by a computing device, the symbol comprising at least four regions meeting at a common vertex and having the colors selected so as to encode the specified digital value using the respective digital codes.

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: Imaging apparatus (28) includes a mosaic image sensor (38), which is configured to capture and output a mosaic image comprising a matrix of pixels that is made up of multiple interleaved sub-matrices, each sub-matrix containing the pixels of a single respective color. Processing circuitry (32) is configured to process the pixels in each of one or more of the sub-matrices separately from the pixels in the other sub-matrices in order to identify in the mosaic image a graphical tag (22) that encodes a digital value in a machine-readable form.

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 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: 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 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.