Patent attributes
A technique for efficiently calibrating a camera is provided. Reference laser scan data is obtained by scanning a building 131 by a laser scanner 115, which is fixed on a vehicle 100 and has known exterior orientation parameters, while the vehicle 100 travels. An image of the building 131 is photographed at a predetermined timing by an onboard camera 113. Reference point cloud position data, in which the reference laser scan data is described in a coordinate system defined on the vehicle 100 at the predetermined timing, is calculated based on the trajectory the vehicle 100 has traveled. Matching points are selected between feature points in the reference point cloud position data and in the image. Exterior orientation parameters of the camera 113 are calculated based on relative relationships between the reference point cloud position data and image coordinate values in the image of the matching points.