Everyone is familiar with the passive infrared and microwave
sensors that are used to activate door openers, security lights and alarm
systems. Less known is the existence of devices that use image processing to
detect motion and trigger alarms, recording and other actions. These are
generally referred to as Video Motion Detection (VMD) sensors.
Whereas a PIR or microwave sensor has a limited range, VMD
sensors can function over very long distances and wide areas because they work
from a video camera image that could be viewing anything from 3m to 5km
away.
Farco Technologies Limited manufacture high-end video motion
detection systems that are used in red light cameras and traffic signal
controllers. They also produce a range of low-cost VMD devices that utilise
high-speed image processing technology.
The "Wachit" is a small, sturdily-housed unit that’s connected
between a video camera and a recording device. It comes equipped with relay
outputs and can directly control a recording device via its inbuilt infrared
remote learning capabilities.
Farco also offer the VMD-19 module for those that wish to use
VMD technology in their own products. The module consists of a small printed
circuit board with the same footprint as a standard 18-pin 0.6-inch wide IC. It
can be directly connected to a composite video source to detect the motion of
objects within the video signal. From the outset, Farco designed the VMD-19 for
easy integration in security cameras, VCR designs, video switchers, quad
processors, multiplexers, etc.
VCR surveillance
