In traffic management and security monitoring, the telephoto occasions are often encountered, selleck chemical for example, for capturing the license plate of an escaping vehicle that has just run a red light. However, all existing zoom tracking methods mentioned previously have been developed for the digital still camera systems. These algorithmic methods assume that the object distance is constant; thus, the moving or switching object in video surveillance [19] has not been considered.Figure 4(a) shows the moving object as the zoom is changed from wide-angle to tele-angle. The object distance is changing as the car moves towards the video camera during zooming. In this situation, existing methods cannot produce an ideal result. There are several other situations in which these methods cannot properly function, Inhibitors,Modulators,Libraries even when the objects are stationary.
Figure 4(b) illustrates the switching object during zooming. The computer box and network switch are shown as two stationary objects at different distances in the scene. When the zoom motor is moved from wide-angle to tele-angle, Inhibitors,Modulators,Libraries the main target in the video changes from the computer box to the network switch. The traditional zoom tracking methods will also fail in this situation.Figure 4.(a) Moving object during zooming; (b) Switching object during zooming.To track moving and switching objects in digital video surveillance and to acquire better estimated results without pre-training the system, we propose the robust Inhibitors,Modulators,Libraries feedback zoom tracking (FZT) method to revise the estimated trace curve, which is based on traditional GZT estimation and utilises a proportional-integral-derivative (PID) loop-closed feedback controller [20�C22].
In the absence of knowledge of the underlying process, a PID controller has historically been considered optimal [23]. The controller can provide control action for specific process requirements by tuning its parameters. This method Inhibitors,Modulators,Libraries Entinostat compensates for errors along the estimated trace curve using the real-time focus value (FV), which is typically used in the auto-focusing function.1.4. Contributions and OrganisationIn this work: (1) we discuss the zoom tracking methods in video surveillance for the first time; (2) we propose a novel zoom tracking method called FZT, which is robust in tracking moving or switching objects in video surveillance; (3) we implement our FZT zoom tracking algorithm on real-time digital video hardware and compare it with commonly used algorithms.
To MEK162 MEK the best of our knowledge, the focus value and real-time feedback mechanism have not yet been used in previous zoom tracking studies, and there have been no previous reports on the implementation of the zoom tracking method in video surveillance devices.This paper is organised as follows. Section 2 introduces our FZT method in detail. The FZT approach is then implemented on the hardware platform in Section 3.