User`s manual

34
AXIS 282/AXIS 282A - Event Configuration
Camera Tampering
The camera tampering
application generates an alarm
whenever the camera is
repositioned, or when the lens is
covered, sprayed or severely put
out of focus. The tampering
application will only become
active and ready after the
camera has not moved for at
least 10 seconds. During this
period the application sets up a
Scene Model to use as a
comparison to detect tampering in current images.
This means that PTZ movements will also reset the applicati
on - if the PTZ movements are
too frequent there will be no tampering alarms. PTZ should be used sparingly when camera
tampering is enabled. For the scene model to be set up properly make sure that the camera
is in focus, the lighting conditions are correct, and the camera is not pointed at a scene
that lacks contours, for example a blank wall.
Settings
Minimum duration - This parameter sets the minimum tamperin
g period, i.e. an alarm
will not be triggered until this period has elapsed, even if the tampering conditions are
otherwise met. This can help prevent false alarms for known conditions that affect the
image.
Alarm for dark images - If the camera lens is sprayed and the image is
darkened, it
will not be possible to distinguish this from other situations where the same effect is seen,
i.e. when the lighting conditions change.
When this parameter is enabled, al
arms will be generated for all cases where the image
turns dark or the lens is sprayed. If not enabled, no alarm will be sent.
Click Save after you define th
ese settings.