Image-based localization using image database and local 3D maps

Image-based localization is one of the most important techniques for autonomous navigation. This paper proposes a 6-DoF localization method based on image database and local 3D maps. To perform localization, the image database and local 3D map of each image are collected in advance. By applying a fast place recognition algorithm such as FAB-MAP, an initial position is assumed to be available at a past position of a matched image from the database. Then, a 6-DoF camera pose is estimated using PnP algorithm by 2D-to-3D matching correspondences in a query image and a local 3D map. The proposed algorithm is demonstrated in real environment.