Feature group matching for appearance-based localization

Local feature matching has become a commonly used method to compare images. For mobile robots, a reliable method for comparing images can constitute a key component for localization tasks. In this paper, we address the issues of appearance-based topological and metric localization by introducing a novel group matching approach to select less but more robust features to match the current robot view with reference images. Feature group matching is based on the consideration that feature descriptors together with spatial relations are more robust than classical approaches. Our datasets, each consisting of a large number of omnidirectional images, have been acquired over different day times (different lighting conditions) both in indoor and outdoor environments. The feature group matching outperforms the SIFT in indoor localization showing better performances both in the case of topological and metric localization. In outdoor SURF remains the best feature extraction method, as reported in literature.