Vivotek FD8167A User Manual page 116

VIVOTEK
This motion detection window will also be displayed on the Event Settings page. You can go to Event
> Event settings > Trigger to select it as a trigger source. Please refer to page 122 for detailed
information.
NOTE:
► How does motion detection work?
A
B
There are two motion detection parameters: Sensitivity and Min. Item Size. As illustrated above, frame
A and frame B are two sequential images. Pixel differences between the two frames are detected and
highlighted in gray in which the sensitivity setting will take effect. Sensitivity is a value that expresses
the sensitivity to moving objects. A higher sensitivity setting allows camera to detect slight movements
while a lower sensitivity setting will neglect them.
The minimum item size is a threshold value that determines how many "alerted pixels" can trigger an
event. When the size of an intruding object is larger than the minimum size, and its movement persist
for 0.3 second, the motion is judged to exceed the defined threshold; and the motion window will be
outlined in red. With a large minimum item size, the size of moving object in frame C is considered as
smaller than the minimum item size, no motion alarm is triggered. With a smaller minimum item size,
the same moving object in frame D triggers the alarm.
For applications that require a high level of security management, it is suggested to use higher
sensitivity settings. However, a higher sensitivity level can also produce false alarms due to fast light
changes when switching between the day and night modes, AE switch, turning the light on or off, etc.
116 - User's Manual
C
Alerted pixels < Min. item size
D
Alerted pixels > Min. item size
Min. item size
Min. item size