US Patent 11122195 Camera parameter estimation device, method, and program

A projection image generation unit 81 applies a plurality of projection schemes that use the radius of a visual field region of a fisheye-lens camera to an image in which an object including a straight line is imaged by the fisheye-lens camera, and generates a plurality of projection images. A projection scheme determination unit 82 selects one of the plurality of projection images on the basis of the linearity of each of the straight lines included in the projection images and determines a projection scheme on the basis of the selected projection image. An output unit 83 outputs an internal parameter of the fisheye-lens camera that corresponds to the determined projection scheme.