June 2015

Path zone – How it works?

Configuring this zone is done on the fixed camera. The zone is drawn along with the path direction. We then specify the exact Pan/Tilt/Zoom position of the PTZ, along with the fixed delay of time to stay on this zone.

When configured, the PTZ camera performs normal tracking operations when nothing special happens into this zone. Once the fixed camera detects an object (vehicle) into this zone, the PTZ is called in priority to move to the previously specified Pan/Tilt/Zoom position. The PTZ will stay in that position for the specified delay. By default, this delay is around 10 seconds. This delay is normally enough to grab a high quality image that allows to read the licence plate. After this period of time, the PTZ goes back to it’s normal tracking operations.

This function is really useful for outside security systems by providing a high level video analytic function without the requirement of dedicated cameras. Incidentally, this function can also count the number of detections in this path zone (ex: number of cars that leaved in a day).

The characteristic of thermal cameras are very different than conventional cameras: even if the thermal camera gives a lot less details than a natural image, the thermal image filters a lot of noise and reveals a lot of information that would be hard to detect, mostly at night.

These special characteristics makes it efficient to detect persons and vehicles at night, in low light and even in full sunlight. The OneTrack system can perform efficiently object detection on those thermal cameras, IP or analog.

Testing performed with thermal cameras with new object detection functions of the OneTrack allowed to detect a pedestrian at night at a distance of around 400 feet, with a minimum of false detections.

AutoTrack camera or MultiTrack system?

PTZ tracking systems essentially works in 2 modes: Autotrack or Multitrack. In Autotrack mode, the PTZ camera detects the motion in the image and positions itself by trying to center the detected object. Of course, when the PTZ is oriented in one direction, it cannot detect what’s going on in the other direction. To perform detection in a 360 deg angle, a tour is required. During the tour, the camera performs the video detection at each step and launches a tracking if required. However, performing a tour requires some time, so it’s possible to miss a fast intrusion.

In Multitrack mode, the video detection is performed on fixed cameras associated to the PTZ. When an object is detected on a fixed camera, the controller positions the PTZ directly on the detected object. The fixed cameras can be positioned to cover the entire zone to monitor. If many objects are detected, the PTZ can jump from one object to the other at a fast speed. Even more, since the detection is done by the fixed cameras, the intelligent video analyzer can classify the objects (car, pedestrian) and filter false objects like reflections on puddles, waving flags, etc. In Autotrack mode, since the PTZ is always moving, there is no background available to perform this kind of classification.