Automatic Multi-Camera Extrinsic Parameter Calibration Based on Pedestrian Torsors

UAV-Assisted Wide Area Multi-Camera Space Alignment Based on Spatiotemporal Feature Map

In this paper, we investigate the problem of aligning multiple deployed camera into one united coordinate system for cross-camera information sharing and intercommunication. However, the difficulty is greatly increased when faced with large-scale scene under chaotic camera deployment. To address this problem, we propose a UAV-assisted wide area multi-camera space alignment approach based on spatiotemporal feature map. It employs the great global perception of Unmanned Aerial Vehicles (UAVs) to meet the challenge from wide-range environment. Concretely, we first present a novel spatiotemporal feature map construction approach to represent the input aerial and ground monitoring data. In this way, the motion consistency across view is well mined to overcome the great perspective gap between the UAV and ground cameras. To obtain the corresponding relationship between their pixels, we propose a cross-view spatiotemporal matching strategy. Through solving relative relationship with the above air-to-ground point correspondences, all ground cameras can be aligned into one surveillance space. The proposed approach was evaluated in both simulation and real environments qualitatively and quantitatively. Extensive experimental results demonstrate that our system can successfully align all ground cameras with very small pixel error. Additionally, the comparisons with other works on different test situations also verify its superior performance.

On-line three-dimensional coordinate measurement of dynamic binocular stereo vision based on rotating camera in large FOV

A dynamic binocular stereo vision (DBSV) based on a non-zoom rotating camera in a large field of view (FOV) is established herein. A novel two-point method is proposed to estimate the initial parameters of the camera quickly. The intrinsic parameters and roll angle of each camera remains constant, and the pitch and yaw angles after the camera rotates are directly estimated from output of high-precision two-axes platform, which makes it possible that three-dimensional (3D) coordinate can be measured online after rotation. Moreover, a target matching algorithm based on moving DLT is proposed to achieve automatic alignment of the camera. The accuracy of 3D coordinate measurement is evaluated on various synthetic and real data, and the DBSV is suitable for occasions where extremely high accuracy is not required in large FOV.