Patent ID: 8831290

Claim:
A method for determining poses of a camera relative to an environment, wherein the camera is movable, comprising: determining point correspondences from a set of initial images acquired of the environment by the camera; applying 2-point motion estimation to the point correspondences to determine a set of initial poses of the camera; and generating a point cloud from the set of initial poses and the point correspondences, and for each next image, performing the steps of: determining the point correspondences from the next image; determining the pose of the camera from the point correspondences of the next image and the point cloud; and updating the point cloud according to the pose and the point correspondences of the next image, wherein the steps are performed in a processor, and wherein the 2-point motion estimation further comprises: obtaining projection rays from the point correspondences; transforming the projection rays in a first camera coordinate system to a first intermediate coordinate system, and a second camera coordinate system to a second intermediate coordinate system; determining motion between the projection rays in the first and second intermediate coordinate systems using a quadratic equation subject to coplanarity and orthonormality constraints; and determining motion between the projection rays in the first and second camera coordinate systems using the motion computed in the first and second intermediate coordinate systems.