Abstract: Systems, devices, features, and methods for detecting geographic features in images, such as, for example, to develop a navigation database are disclosed. For example, a method of detecting a path marking from collected images includes collecting a plurality of images of geographic areas along a path. An image of the plurality of images is selected. Components that represent an object on the path in the selected image are determined. In one embodiment, the determined components are independent or invariant to scale of the object. The determined components are compared to reference components in a data library. If the determined components substantially meet a matching threshold with the reference components, the object in the selected image is identified to be a path marking corresponding to the reference components in the data library.

Abstract: Systems, devices, features, and methods for determining geographic position information from an image are disclosed. For example, one method for determining the geographic position information is used to develop a navigation database. The method comprises capturing a plurality of images of geographic features by a camera mounted on a vehicle or a pedestrian. A single image from the plurality of images is identified or selected. A real-world ground distance between a reference ground point in the single image and a ground point corresponding to an object in the single image is determined based on determined calibration values corresponding to the camera. Real-world geographic position information, such as a latitude coordinate and a longitude coordinate, of the ground point corresponding to the object in the single image is determined based on the determined real-world ground distance.

Abstract: Systems, devices, features, and methods for detecting geographic features in images, such as, for example, to develop a navigation database are disclosed. For example, a method of detecting a path marking from collected images includes collecting a plurality of images of geographic areas along a path. An image of the plurality of images is selected. Components that represent an object on the path in the selected image are determined. In one embodiment, the determined components are independent or invariant to scale of the object. The determined components are compared to reference components in a data library. If the determined components substantially meet a matching threshold with the reference components, the object in the selected image is identified to be a path marking corresponding to the reference components in the data library.

Abstract: Systems, devices, features, and methods for determining geographic position information from an image are disclosed. For example, one method for determining the geographic position information is used to develop a navigation database. The method comprises capturing a plurality of images of geographic features by a camera mounted on a vehicle or a pedestrian. A single image from the plurality of images is identified or selected. A real-world ground distance between a reference ground point in the single image and a ground point corresponding to an object in the single image is determined based on determined calibration values corresponding to the camera. Real-world geographic position information, such as a latitude coordinate and a longitude coordinate, of the ground point corresponding to the object in the single image is determined based on the determined real-world ground distance.

Abstract: A method for determining a polygonal intersection of a first polygon and a second polygon. An intersection of the boundary of the first polygon with the boundary of the second polygon is located by finding a point from which at least three portions of boundaries extend. From this point, a first portion of the boundary of the polygonal intersection is determined by identifying a portion of the boundary of the first polygon that is located inside the second polygon. Each subsequent portion of the boundary of the polygonal intersection is determined by selecting that portion of the boundary of either the first polygon or the second polygon that (1) connects to a leading end of a current portion of the boundary of the polygonal intersection and (2) forms the least angle with the current portion of the boundary of the polygonal intersection.

Abstract: A method for constructing a polygon from data representations of a given plurality of links. A first point of a candidate polygon is determined by selecting a point located on one of the given plurality of links. Then, a first known link that forms part of the boundary of a candidate polygon is determined to be that link upon which the first point is located. The orientation of the first known link is determined. Then, each subsequent known link that forms part of the boundary of the candidate polygon is determined by selecting from the given plurality of links that link (1) that connects to an end of a known link in a chosen direction and (2) that forms a minimum rotation angle therewith in a chosen rotational direction. After determining that the candidate polygon is a complete polygon, any links from the given plurality of links that are not shared by the complete polygon with any other candidate polygon are removed from the given plurality of links.

Abstract: A method for determining a polygonal intersection of a first polygon and a second polygon. An intersection of the boundary of the first polygon with the boundary of the second polygon is located by finding a point from which at least three portions of boundaries extend. From this point, a first portion of the boundary of the polygonal intersection is determined by identifying a portion of the boundary of the first polygon that is located inside the second polygon. Each subsequent portion of the boundary of the polygonal intersection is determined by selecting that portion of the boundary of either the first polygon or the second polygon that (1) connects to a leading end of a current portion of the boundary of the polygonal intersection and (2) forms the least angle with the current portion of the boundary of the polygonal intersection.