US Patent 11430206 Branch-and-bound search algorithm for 4D camera localization

In some implementations, a method includes: extracting key-points from a reference image associated with a scene; generating a multi-cone structure including cones based on the key-points and intrinsic parameters, wherein an apex of the cones corresponds to a camera origin point associated with the reference image, and wherein each axis of the cones intersects a respective key-point; aligning the multi-cone structure based on a nominal alignment vector in order to restrict two rotational degrees of freedom; and determining a rigid transformation for the multi-cone structure, including a value for a remaining rotational degree of freedom and values for three translational degrees of freedom, within a search space associated with the scene, wherein a number of the cones within the multi-cone structure that include at least one point in a three-dimensional (3D) point cloud associated with the scene is maximal when the multi-cone structure is transformed by the rigid transformation.