Abstract: An approach is provided for rendering a distance marker in an image. The approach, for example, involves determining a plurality of camera characteristics of a camera used to capture the image. The plurality of camera characteristics, for instance, can include a camera field of view, a horizon offset, a camera mounting height, a camera mounting axis, or a combination thereof. The approach also involves determining a ground plane extending to a horizon depicted in the image, a camera position with respect to the ground plane, and an image plane based on the plurality of characteristics, wherein the image plane is orthogonal to the ground plane and intersects the ground plane at a designated distance from the camera position. The approach further involves projecting a ray from the camera position through the distance marker on the ground plane to a marker position on the image plane, and rendering the distance marker in the image based on the marker position on the image plane.

Abstract: An approach is provided for rendering a distance marker in an image. The approach, for example, involves determining a plurality of camera characteristics of a camera used to capture the image. The plurality of camera characteristics, for instance, can include a camera field of view, a horizon offset, a camera mounting height, a camera mounting axis, or a combination thereof. The approach also involves determining a ground plane extending to a horizon depicted in the image, a camera position with respect to the ground plane, and an image plane based on the plurality of characteristics, wherein the image plane is orthogonal to the ground plane and intersects the ground plane at a designated distance from the camera position. The approach further involves projecting a ray from the camera position through the distance marker on the ground plane to a marker position on the image plane, and rendering the distance marker in the image based on the marker position on the image plane.

Abstract: A method for collecting data for a geographic database is disclosed. Altitude data are collected using a vehicle traveling in a geographic region. A barometer associated with the vehicle supplies the altitude data. Road grade data along the roads traveled by the vehicle is derived by analyzing the altitude data. The geographic database is updated to indicate the road grade.

Abstract: A bounding route is calculated between two physical locations to determine a boundary value for which subsequent route calculations or portions thereof may be compared to. The bounding route may be calculated by selecting segments of roads that satisfy certain criteria. These criteria may be based on weighting factors or parameters such as the “least distance traveled” or the “least travel time.” The bounding route and the value may then provide any route calculation program with criteria used to determine whether a search at a particular location should continue. That is, if a search at a particular location has exceeded the criteria, or equivalently, the search has gone beyond the boundary, the search is stopped because it will most likely result in an un-optimal route. This process may then be an iterative one until an optimal search with a value less than the boundary value is found.