Urban dual mode video detection system based on fisheye and PTZ cameras

This work presents an artificial vision-based monitoring system for urban environments. It comprises a fisheye camera monitoring the scenes 180ox360o hemisphere and a Pan-Tilt-Zoom camera capturing narrower regions of interest in high-resolution. The ONVIF protocol standard is used to interface both IP-cameras, allowing for the integration of camera control (image acquisition and movement) and geometric calculations on a single device. The events of interest (motion of vehicles and pedestrians) are assumed to happen on the ground plane. This assumption is required to solve the back-projection, the function that maps coordinates in the highly distorted images of the fisheye camera to the ground plane. A calibration strategy estimates the poses of the cameras without placing restrictions on their orientations or relative distance. It optimizes the back-projection error in the ground plane instead of the re-projection error in the image. Finally, a simple pointing and zoom adjustment strategy controls the Pan-Tilt-Zoom camera. The system is tested in controlled laboratory conditions and shows accurate outdoor performance for pedestrian observation.

Automated summary

This work introduces an artificial vision-based monitoring system for urban environments, utilizing fisheye and Pan-Tilt-Zoom cameras connected via the ONVIF protocol. A calibration strategy estimates camera poses and optimizes back-projection error in the ground plane, showing accurate outdoor performance for pedestrian observation.