Increasing the Convergence Domain of RGB-D Direct Registration Methods for Vision-based Localization in Large Scale Environments

International audienceDeveloping autonomous vehicles capable of dealing with complex and dynamic unstructured environments over large-scale distances, remains a challenging goal. One of the major difficulties in this objective is the precise localization of the vehicle within its environment so that autonomous navigation techniques can be employed. In this context, this paper presents a methodology to map building and to efficient pose computation which is specially adapted for cases of large displacements. Our method uses hybrid robust RGB-D cost functions that have different convergence properties, whilst exploiting the visibility rotation invariance given by panoramic spherical images. The proposed registration model is composed of a RGB and point-to-plane ICP cost in a multi-resolution framework. We close up the paper presenting mapping and localization results in real outdoor scenes

Adaptive Direct RGB-D Registration and Mapping for Large Motions

International audienceDense direct RGB-D registration methods are widely used in tasks ranging from localization and tracking to 3D scene reconstruction. This work addresses a peculiar aspect which drastically limits the applicability of direct registration, namely the weakness of the convergence domain. First, we propose an activation function based on the conditioning of the RGB and ICP point-to-plane error terms. This function strengthens the geometric error influence in the first coarse iterations, while the intensity data term dominates in the finer increments. The information gathered from the geometric and photometric cost functions is not only considered for improving the system observability, but for exploiting the different convergence properties and convexity of each data term. Next, we develop a set of strategies as a flexible regularization and a pixel saliency selection to further improve the quality and robustness of this approach. The methodology is formulated for a generic warping model and results are given using perspective and spherical sensor models. Finally, our method is validated in different RGB-D spherical datasets, including both indoor and outdoor real sequences and using the KITTI VO/SLAM benchmark dataset. We show that the different proposed techniques (weighted activation function, regularization, saliency pixel selection), lead to faster convergence and larger convergence domains, which are the main limitations to the use of direct methods