Vivotek NETWORK CAMERA IZ7151 - Manual (Page 50)

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NOTE :
► In a privacy mask window, motion detection will not take effect.
WindowA X
► How does motion detection work?
A
B D
C
There are two parameters for setting the motion detection: Sensitivity and Percentage. In the
illustration above, frame A and frame B are two sequential images. Pixel differences between
the two frames are detected and highlighted in gray (frame C), and will be compared with the
sensitivity setting. Sensitivity is a value that expresses the sensitivity to moving objects. Higher
sensitivity settings are expected to sense a slight movement while smaller sensitivity settings
tend to neglect it. When the sensitivity is set to 70%, the Network Camera defines the pixels in
the purple areas as “alerted pixels” (frame D).
Percentage is a value that expresses the proportion of “alerted pixels” to all pixels in the
motion detection window. In this case, 50% of pixels are identified as “alerted pixels”. When the
percentage is set to 30%, the motions are judged to exceed the defined threshold; therefore, the