Patent ID: 8731305

Claim:
A computer-implemented method of updating map data using satellite imagery, comprising: identifying a road segment within the map data, the satellite imagery indicating that the road segment is at a different geographic position than a geographic position indicated by the map data; generating cost function values for a cost function measuring a likelihood that pixels of the satellite imagery show a road, generating the cost function values comprising: computing Hessian matrices for pixels of an image of the satellite imagery, the Hessian matrices producing eigenvectors for the pixels; and determining direction values for the pixels responsive to the pixels' eigenvectors using the cost function; identifying an endpoint of the road segment within the map data aligned with a corresponding endpoint of the road segment in the satellite imagery; applying a road template at the corresponding endpoint in the satellite imagery; determining an angle of the road template that matches an angle of the road segment indicated by the satellite imagery by optimizing the cost function based at least in part on cost function values assigned to pixels of the satellite imagery within a boundary of the road template; updating the geographic position of the road segment within the map data using the responsive to the determined angle of the road template; and storing the updated geographic position of the road segment with the map data.