Monocular visual odometry aided by a low resolution time of flight camera

Abstract

In this paper we describe a Visual Odometry algorithm using a single RGB camera and a low resolution Time-ofFlight (ToF) camera for resolving the scale ambiguity in monocular vision. Two hybrid 3D-to-2D approaches for integrating direct depth measurements from the ToF with the RGB camera are compared. These two methods differ in the association of RGB and ToF camera measurements: one is performed in the 3D space, the other in the image space. The performances of these two approaches are compared using an external measurement system as reference. An important contribution of this paper is that the algorithm is tailored for an inexpensive ToF camera with a very small field-of-view (8.7° × 8.7°) and resolution (8 × 8 pixels). The reason of this choice is that such a ToF camera can be easily integrated in a space oriented measurement system, without a significant increase in mass, dimensions and cost.