VIVOTEK
User's Manual - 135
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 119 for
► How does motion detection work?
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.
A
B
D
C
Min. item size
Alerted pixels < Min. item size
Alerted pixels > Min. item size
Min. item size
NOTE:
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