Reconstruction of 3D Urban Scenes Using a Moving Lidar Sensor

In this report, we propose algorithms which interpret and display 3D environments.The input of this procedure is a LiDAR sensor mounted atop of a car. The sensor outputs a data stream covering more than 100 meters radius of space, collecting data at 15Hz. The recording is done in real environment on the streets of Budapest in real time, while the processing is offline, implemented on CPU keeping in mind the future implementation on GPUs to reach real time data processing. The aim is to segment several region classes (such as roads, building walls, vegetation) and to identify specified objects (such as people, vehicles, traffic signs) in the point clouds through a presegmentation step. To achieve this classification, we need several features such as the color and geometrical properties of the specified objects and their possible geometrical and physical interactions. Also, we need to take into account the time domain features calculated based on the LiDAR data stream. After this presegmentation step we are able to reconstruct building facades in 3D and to track the detected objects in the 3D space. Also, in the future, this processed data set can be registered against 2D images provided by conventional cameras to reproduce realistic, colored 3D virtua

Towards 4D Virtual City Reconstruction From Lidar Point Cloud Sequences

In this paper we propose a joint approach on virtual city reconstruction and dynamic scene analysis based on point cloud sequences of a single car-mounted Rotating Multi-Beam (RMB) Lidar sensor. The aim of the addressed work is to create 4D spatio-temporal models of large dynamic urban scenes containing various moving and static objects. Standalone RMB Lidar devices have been frequently applied in robot navigation tasks and proved to be efficient in moving object detection and recognition. However, they have not been widely exploited yet for geometric approximation of ground surfaces and building facades due to the sparseness and inhomogeneous density of the individual point cloud scans. In our approach we propose an automatic registration method of the consecutive scans without any additional sensor information such as IMU, and introduce a process for simultaneously extracting reconstructed surfaces, motion information and objects from the registered dense point cloud completed with point time stamp information

Mixed Reality using a Lidar and a 4D Studio

In this demo we present a system for creation and visualization of mixed reality by combining the spatio-temporal model of a real outdoor environment with the models of people acting in a studio. We use a LIDAR sensor to measure a scene with walking pedestrians, detect and track them, then reconstruct the static scene part. The scene is then modified and populated by human avatars created in a 4D reconstruction studio

Method And System For Generating A Three-Dimensional Model

The invention is a method for generating a three-dimensional model, said method comprising generating (S100), by means of a scanning device, a point set corresponding to a scene comprising at least one object shape, dividing (S120) the point set corresponding to the scene into a foreground point set corresponding to a foreground of the scene, and comprising a subset corresponding to the at least one object shape of the point set corresponding to the scene, and a background point set corresponding to a background of the scene, separating (S130) from the foreground point set, at least one object shape subset corresponding to each of the at least one object shape, respectively, generating (S140) a background three-dimensional model on the basis of the background point set, generating (S150) from optical recordings a three-dimensional model of at least one substituting object shape assignable to each of the at least one object shape, respectively, and generating (S160) a combined three-dimensional model on the basis of the background three-dimensional model and the three- dimensional model of at least one substituting object shape substituting each of the at least one object shape subset, respectively. Furthermore, the invention is a system for generating a three-dimensional model