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Method to Calculate the Location of a Photographic Object and for Automatic Tagging Disclosure Number: IPCOM000132067D
Original Publication Date: 2005-Nov-30
Included in the Prior Art Database: 2005-Dec-01
Document File: 2 page(s) / 44K

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A method is described that uses simple mechanisms and calculations to calculate the location of a photographic subject. By recording appropriate sensor values, the location of the subject is easily calculated so that the photographer and the subject can be located geographically.

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Method to Calculate the Location of a Photographic Object and for Automatic Tagging

Digital cameras today are often designed with a GPS sensor that records the location of the photographer when a photograph is taken. The coordinates (latitude, longitude, altitude) are easily recorded in any photographic format such as defined in the well-known JPEG specification. Film cameras can record the same information by encoding the data onto the film (e.g., between the sprocket holes) or on a transparent magnetic backing layer. Similarly, motion picture and video cameras can record the information continuously onto their recording media.

The location of the photographer may be of interest, but the location of the photographic subject is usually of greater interest, especially since one can then use the information to plot or otherwise incorporate the location of the subject in another computer program (e.g., in a GIS mapping program or in a locale visualization program). Simple sensors added to a camera can be used to compute the likely location of the subject of the photograph. There is some error range in the process that can be determined.

Design a camera to include the following sensors to record these values: a GPS sensor to measure the 3-space location of the photographer, an angle-of-inclination sensor to measure the lens angle with respect to horizontal, and a compass to measure the direction in which the lens is pointing. The camera should also record the lens focus setting, but this is commonly done in existing practice. Many cameras include a so-called portrait-landscape orientation sensor and that information can be recorded. Starting from the location of the photographer, the distance to the object is simply the measurement of the focus setting of the camera lens. This calculation places the photographic subject on a three-dimensional sphere centered on the photographer. Then apply the compass setting (adjusted for declination and deviation, using tables keyed to the GPS reading and other calibration techniques) to calculate the location of the photographic subject on a circle in 3-space centered on the photographer (this is a semi-circle around the photographer that is oriented vertically and facing in the direction in which the compass is po...