A method, apparatus, system, and computer program product provide the ability to extract level information and reference grid information from point cloud data. Point cloud data is obtained and organized into a three-dimensional structure of voxels. Potential boundary points are filtered from the boundary cells. Level information is extracted from a Z-axis histogram of the voxels positioned along the Z-axis of the three-dimensional voxel structure and further refined. Reference grid information is extracted from an X-axis histogram of the voxels positioned along the X-axis of the three-dimensional voxel structure and a Y-axis histogram of the voxels positioned along the Y-axis of the three-dimensional voxel structure and further refined.