Abstract: To determine the location of a querying mobile device, a request is received from the querying mobile device via a communication network. One or several participating mobile devices that potentially are physically proximate to the querying mobile device are identified. A request to scan for a location broadcast message transmitted by the querying mobile device is sent to the participating mobile devices. One or more location broadcast reports from participating mobile devices are received, where each received location broadcast report indicates that the location broadcast message was received at the corresponding participating mobile device. The location of the querying mobile device is estimated based on (i) the received one or more location broadcast reports and (ii) respective locations of the participating mobile devices from which the one or more location broadcast reports were received.

Abstract: A mobile device receives signals from transmitting devices and generates sets of signal metrics based on the received signals. The mobile device also receives indicated locations, where each indicated location is associated with a respective set of signal metrics. The mobile device provides location-specific data to a transmitting device locating engine to estimate locations of the transmitting devices, where the location-specific data includes data representing the sets of signal metrics and data representing the indicated locations. The mobile device further receives an indication of sharing criteria via a user interface of the mobile device, and causes the estimated locations to be selectively shared with one or more other mobile devices based on the sharing criteria.

Abstract: To determine the location of a querying mobile device, a request is received from the querying mobile device via a communication network. One or several participating mobile devices that potentially are physically proximate to the querying mobile device are identified. A request to scan for a location broadcast message transmitted by the querying mobile device is sent to the participating mobile devices. One or more location broadcast reports from participating mobile devices are received, where each received location broadcast report indicates that the location broadcast message was received at the corresponding participating mobile device. The location of the querying mobile device is estimated based on (i) the received one or more location broadcast reports and (ii) respective locations of the participating mobile devices from which the one or more location broadcast reports were received.

Abstract: Assets of raw geo-located imagery can be divided into tiles and coverage masks can be generated for each tile. For each tile, fragments of pixels from coverage masks of neighboring tiles can be extracted and tagged. The fragments can be sorted and stored in a data structure so that fragments having the same tag can be grouped together in the data structure. The fragments can be used to feather the coverage mask of the tile to produce a blend mask. Multi-resolution imagery and mask pyramids can be generated by extracting fragments from tiles and minified (e.g., down-sampled). The minified fragments can be tagged (e.g., by ancestor tile name), sorted and stored in a data structure, so that fragments having like tags can be stored together in the data structure. The fragments can be assembled into fully minified tiles for each level in the pyramid.

Abstract: To determine the location of a querying mobile device, a request is received from the querying mobile device via a communication network. One or several participating mobile devices that potentially are physically proximate to the querying mobile device are identified. A request to scan for a location broadcast message transmitted by the querying mobile device is sent to the participating mobile devices. One or more location broadcast reports from participating mobile devices are received, where each received location broadcast report indicates that the location broadcast message was received at the corresponding participating mobile device. The location of the querying mobile device is estimated based on (i) the received one or more location broadcast reports and (ii) respective locations of the participating mobile devices from which the one or more location broadcast reports were received.

Abstract: A mobile device receives signals from transmitting devices and generates sets of signal metrics based on the received signals. The mobile device also receives indicated locations, where each indicated location is associated with a respective set of signal metrics. The mobile device provides location-specific data to a transmitting device locating engine to estimate locations of the transmitting devices, where the location-specific data includes data representing the sets of signal metrics and data representing the indicated locations. The mobile device further receives an indication of sharing criteria via a user interface of the mobile device, and causes the estimated locations to be selectively shared with one or more other mobile devices based on the sharing criteria.

Abstract: Embodiments of this invention relates to orthorectifying oblique imagery to a nadir view. In an embodiment, a method orthorectifies oblique photographic imagery. An oblique photographic image is projected onto a three-dimensional model of terrain. Points are sampled from the projected photographic image at the intersection of the three-dimensional model of terrain and parallel rays extended from a virtual viewport having a nadir perspective. The sampled points are assembled into an orthorectified image. Finally, the orthorectified image or the sampled points are adjusted approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image. Each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.

Abstract: Assets of raw geo-located imagery can be divided into tiles and coverage masks can be generated for each tile. For each tile, fragments of pixels from coverage masks of neighboring tiles can be extracted and tagged. The fragments can be sorted and stored in a data structure so that fragments having the same tag can be grouped together in the data structure. The fragments can be used to feather the coverage mask of the tile to produce a blend mask. Multi-resolution imagery and mask pyramids can be generated by extracting fragments from tiles and minified (e.g., down-sampled). The minified fragments can be tagged (e.g., by ancestor tile name), sorted and stored in a data structure, so that fragments having like tags can be stored together in the data structure. The fragments can be assembled into fully minified tiles for each level in the pyramid. Input tiles in a first projection are re-projected into a second projection using techniques that minimize distortion in the re-projected imagery.

Abstract: Methods and systems for updating mosaics of digital source images are disclosed. According to one embodiment, a method for updating a mosaic of digital source images includes segmenting the mosaic to regions, generating a plurality of region-statistics where each region-statistics correspond to image characteristics of one region, organizing the plurality of region-statistics in a database, and updating the mosaic using at least one target region-statistics from the organized plurality of region-statistics. Updating the mosaic can include color correcting. The method for updating a mosaic of digital source images can also includes optimizing the organized plurality of region-statistics, wherein the optimizing is based on one or more reference region-statistics from the organized plurality of region-statistics.

Abstract: Assets of raw geo-located imagery can be divided into tiles and coverage masks can be generated for each tile. For each tile, fragments of pixels from coverage masks of neighboring tiles can be extracted and tagged. The fragments can be sorted and stored in a data structure so that fragments having the same tag can be grouped together in the data structure. The fragments can be used to feather the coverage mask of the tile to produce a blend mask. Multi-resolution imagery and mask pyramids can be generated by extracting fragments from tiles and minified (e.g., down-sampled). The minified fragments can be tagged (e.g., by ancestor tile name), sorted and stored in a data structure, so that fragments having like tags can be stored together in the data structure. The fragments can be assembled into fully minified tiles for each level in the pyramid. Input tiles in a first projection are re-projected into a second projection using techniques that minimize distortion in the re-projected imagery.

Abstract: Embodiments of this invention relates to orthorectifying oblique imagery to a nadir view. In an embodiment, a method orthorectifies oblique photographic imagery. An oblique photographic image is projected onto a three-dimensional model of terrain. Points are sampled from the projected photographic image at the intersection of the three-dimensional model of terrain and parallel rays extended from a virtual viewport having a nadir perspective. The sampled points are assembled into an orthorectified image. Finally, the orthorectified image or the sampled points are adjusted approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image. Each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.

Abstract: An oblique photographic image is projected onto a three-dimensional model of terrain. Points are sampled from the projected photographic image at the intersection of the three-dimensional model of terrain and parallel rays extended from a virtual viewport having a nadir perspective. The sampled points are assembled into an orthorectified image. Finally, the orthorectified image or the sampled points are adjusted approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image. Each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.

Abstract: Assets of raw geo-located imagery can be divided into tiles and coverage masks can be generated for each tile. For each tile, fragments of pixels from coverage masks of neighboring tiles can be extracted and tagged. The fragments can be sorted and stored in a data structure so that fragments having the same tag can be grouped together in the data structure. The fragments can be used to feather the coverage mask of the tile to produce a blend mask. Multi-resolution imagery and mask pyramids can be generated by extracting fragments from tiles and minified (e.g., down-sampled). The minified fragments can be tagged (e.g., by ancestor tile name), sorted and stored in a data structure, so that fragments having like tags can be stored together in the data structure. The fragments can be assembled into fully minified tiles for each level in the pyramid. Input tiles in a first projection are re-projected into a second projection using techniques that minimize distortion in the re-projected imagery.

Abstract: Embodiments of this invention relates to orthorectifying oblique imagery to a nadir view. In an embodiment, a method orthorectifies oblique photographic imagery. An oblique photographic image is projected onto a three-dimensional model of terrain. Points are sampled from the projected photographic image at the intersection of the three-dimensional model of terrain and parallel rays extended from a virtual viewport having a nadir perspective. The sampled points are assembled into an orthorectified image. Finally, the orthorectified image or the sampled points are adjusted approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image. Each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.

Abstract: A computer-implemented method is described. The method includes generating a coarse resolution image from a finer resolution image, generating a coarse coverage mask that identifies valid and non-valid data in the coarse resolution image, and determining whether data in the finer resolution image is valid or non-valid data based on whether corresponding data identified by the coarse coverage mask is valid or non-valid data. In certain embodiments, generating a coarse resolution image can include segmenting the finer resolution image into tiles and compressing each tile. Compressing each tile can be preformed using a lossless compression, and at least two tiles can be transmitted to separate computing devices and compressed in parallel.