Merging of 3D visual maps based on part-map retrieval and path consistency

This paper presents a map-merging method which builds a 3D visual map by connecting part maps. The purpose is to increase flexibility and robustness in 3D mapping. Map merging is performed by combining image retrieval using bag-of-words, geometric verification, and pose adjustment. A key issue is robust data association. To cope with false matches, we perform group matching with pose propagation, which checks the geometric consistency of point correspondences over multiple frames. Also, we perform path consistency check, which examines the accumulated errors along a loop to eliminate inconsistent part map connections. Experiments show our method successfully built detailed 3D maps of indoor environments.