Trajectography of an Uncalibrated Stereo Rig in Urban Environments

This paper describes an original method to compute the relative motion of an uncalibrated stereo rig in urban environments from features lying on the road. The extraction of significant reliable features on the road remains the critical step of this method. We nevertheless detect them according to the stereo constraints and an a priori knowledge on the scene. The motion between two frames of the stereo rig is considered as rigid: the homography computation is enforced by the redundancy of the feature locations in multiple views. The method has been tested on video sequences recorded from a test vehicle that was driven in an urban environments. Promising results from these experiments will be presented

Vehicle Trajectory from an Uncalibrated Stereo-Rig with Super-Homography

International audienceWe present in this article an original manner to estimate the trajectory of a vehicle running in urban-like areas. The method consists in extracting then tracking features (points, lines) with an uncalibrated stereo-rig from the road assumed as a plane to compute homographies relative to the camera(s) motions. The purposed method copes with the dense traffic conditions: the free space required (first ten meters in front of the vehicle) is slightly equivalent to the security distance between two vehicles. Experimental issues from real data are presented and discussed

What can be done with an embedded stereo-rig in urban environments?

International audienceThe development of the Autonomous Guided Vehicles (AGVs) with urban applications are now possible due to the recent solutions (DARPA Grand Challenge) developed to solve the Simultaneous Localization And Mapping (SLAM) problem: perception, path planning and control. For the last decade, the introduction of GPS systems and vision have been allowed the transposition of SLAM methods dedicated to indoor environments to outdoor ones. When the GPS data are unavailable, the current position of the mobile robot can be estimated by the fusion of data from odometer and/or Inertial Navigation System (INS). We detail in this article what can be done with an uncalibrated stereo-rig, when it is embedded in a vehicle which is going through urban roads. The methodology is based on features extracted on planes: we mainly assume the road at the foreground as the plane common to all the urban scenes but other planes like vertical frontages of buildings can be used if the features extracted on the road are not enough relevant. The relative motions of the coplanar features tracked with both cameras allow us to stimate the vehicle ego-motion with a high precision. Futhermore, the features which don't check the relative motion of the considered plane can be assumed as obstacles

Real-time Vehicle Motion Estimation Using Texture Learning and Monocular Vision

High integrity localization system is an important challenge to improve safety for road vehicles. A way to meet the requirements is to fuse information from several sensors, from position and orientation sensors to motion, speed and acceleration sensors. This paper tackles the problem of vehicle motion estimation using monocular vision. A geometric model of the road is used to learn a texture patch in the current image, this patch is then tracked through the successive frames to estimate in real time the motion of the vehicle. The proposed method was assessed using a centimeter accuracy Real Time Kinematic GPS receiver

Constrained camera motion estimation and 3D reconstruction

The creation of virtual content from visual data is a tedious task which requires a high amount of skill and expertise. Although the majority of consumers is in possession of multiple imaging devices that would enable them to perform this task in principle, the processing techniques and tools are still intended for the use by trained experts. As more and more capable hardware becomes available, there is a growing need among consumers and professionals alike for new flexible and reliable tools that reduce the amount of time and effort required to create high-quality content. This thesis describes advances of the state of the art in three areas of computer vision: camera motion estimation, probabilistic 3D reconstruction, and template fitting. First, a new camera model geared towards stereoscopic input data is introduced, which is subsequently developed into a generalized framework for constrained camera motion estimation. A probabilistic reconstruction method for 3D line segments is then described, which takes global connectivity constraints into account. Finally, a new framework for symmetry-aware template fitting is presented, which allows the creation of high-quality models from low-quality input 3D scans. Evaluations with a broad range of challenging synthetic and real-world data sets demonstrate that the new constrained camera motion estimation methods provide improved accuracy and flexibility, and that the new constrained 3D reconstruction methods improve the current state of the art.Die Erzeugung virtueller Inhalte aus visuellem Datenmaterial ist langwierig und erfordert viel Geschick und Sachkenntnis. Obwohl der Großteil der Konsumenten mehrere Bildgebungsgeräte besitzt, die es ihm im Prinzip erlauben würden, dies durchzuführen, sind die Techniken und Werkzeuge noch immer für den Einsatz durch ausgebildete Fachleute gedacht. Da immer leistungsfähigere Hardware zur Verfügung steht, gibt es sowohl bei Konsumenten als auch bei Fachleuten eine wachsende Nachfrage nach neuen flexiblen und verlässlichen Werkzeugen, die die Erzeugung von qualitativ hochwertigen Inhalten vereinfachen. In der vorliegenden Arbeit werden Erweiterungen des Stands der Technik in den folgenden drei Bereichen der Bildverarbeitung beschrieben: Kamerabewegungsschätzung, wahrscheinlichkeitstheoretische 3D-Rekonstruktion und Template-Fitting. Zuerst wird ein neues Kameramodell vorgestellt, das für die Verarbeitung von stereoskopischen Eingabedaten ausgelegt ist. Dieses Modell wird in der Folge in eine generalisierte Methode zur Kamerabewegungsschätzung unter Nebenbedingungen erweitert. Anschließend wird ein wahrscheinlichkeitstheoretisches Verfahren zur Rekonstruktion von 3D-Liniensegmenten beschrieben, das globale Verbindungen als Nebenbedingungen berücksichtigt. Schließlich wird eine neue Methode zum Fitting eines Template-Modells präsentiert, bei der die Berücksichtigung der Symmetriestruktur des Templates die Erzeugung von Modellen hoher Qualität aus 3D-Eingabedaten niedriger Qualität erlaubt. Evaluierungen mit einem breiten Spektrum an anspruchsvollen synthetischen und realen Datensätzen zeigen, dass die neuen Methoden zur Kamerabewegungsschätzung unter Nebenbedingungen höhere Genauigkeit und mehr Flexibilität ermöglichen, und dass die neuen Methoden zur 3D-Rekonstruktion unter Nebenbedingungen den Stand der Technik erweitern

Remote Sensing of Earth Resources: A literature survey with indexes (1970 - 1973 supplement). Section 1: Abstracts

Abstracts of reports, articles, and other documents introduced into the NASA scientific and technical information system between March 1970 and December 1973 are presented in the following areas: agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, oceanography and marine resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis