Real-Time 3D Reconstruction Sponsored partially by: Siemens Scientific Director: Nassir Navab Contact Person: Alexander Ladikos

Keywords: Computer Vision

Abstract

We are working on a real-time 3D reconstruction system aimed at recovering the 3D shape of objects inside a working area using only camera images. The working area is observed by 16 cameras mounted on the ceiling. Using these images we reconstruct an occupancy map and extract individual objects. The long-term goal of the project is to use this occupancy map to detect possible collisions between a robot placed in the working area and other objects in its path.

Detailed Project Description

Camera Calibration and Synchronization

For the calibration we use a method proposed by Svoboda et. al in 'A Convenient Multi-Camera Self-Calibration for Virtual Environments'. It is a factorization-based method which allows to deal with missing data. Its biggest advantage is the ease of use for the end-user who only needs to move an LED through the room to calibrate the system.
the synchronization is performed using a trigger signal generated by a custom-built triggering device.

Reconstruction algorithm

To achieve a real-time reconstruction we use a octree-based visual hull algorithm which has been efficiently implemented on a multi-core architecture. The silhouette images needed for the reconstruction are generated using a background-subtraction method which also compensates for illumination changes and shadows.

System architecture

We use a distributed system architecture to allow the system to scale more easily and to achieve a better performance.

Pictures

Figure 1: Reconstruction results. The images in the corners show 3 of the 16 input views.

Figure 2: The cameras are mounted on movable profiles on the ceiling of the room.

Figure 3: Layout of the lab including the camera positions.

Figure 4: Segmentation results

Videos

Reconstruction results obtained with our system.

Team

Contact Person

Alexander Ladikos

Working Group

Alexander Ladikos

Nassir Navab

Selim Benhimane

Location

Technische Universität München Institut für Informatik / I16 Boltzmannstr. 3 85748 Garching bei München Tel.: +49 89 289-17058 Fax: +49 89 289-17059

Visit our lab at Garching.



internal project page

Please contact Alexander Ladikos for available student projects within this research project.