Bosch VideoJet X10, Инструкция по установке и эксплуатации

Страница: 68 / 132

68 en | Configuration Using a Web Browser VideoJet X10
V3.0 | 2007.09 Installation and Operating Manual Bosch Security Systems
5.23.7 Tamper Detection
You can reveal the tampering of cameras and video cables by means of various options. Run a
series of tests at different times of the day and night to ensure that the video sensor is
operating as intended.
5.23.8 Sensitivity
The basic sensitivity of the tamper detection can be adjusted for the environmental conditions
to which the camera is subject.
The algorithm reacts to the differences between the reference image and the current video
image. The darker the observation area, the higher the value that must be selected.
5.23.9 Trigger delay (s)
You can set delayed alarm triggering. The alarm is only triggered after a set time interval in
seconds has elapsed and then only if the triggering condition still exists. If the original
condition has been restored before this time interval elapses, the alarm is not triggered. This
allows you to avoid false alarms triggered by short-term changes, for example cleaning
activities in the direct field of vision of the camera.
5.23.10 Global change
You can set how large the global change in the video image must be for an alarm to be
triggered. This setting is independent of the sensor fields selected under
Select area . Set a
high value if fewer sensor fields need to change to trigger an alarm. With a low value, it is
necessary for changes to occur simultaneously in a large number of sensor fields to trigger an
alarm.
This option allows you to detect, independently of motion alarms, manipulation of the
orientation or location of a camera resulting from turning the camera mount bracket, for
instance.
5.23.11 Scene too bright
Activate this function if tampering associated with exposure to extreme light (for instance,
shining a flashlight directly on the lens) should trigger an alarm. The average brightness of the
scene provides a basis for recognition.
5.23.12 Scene too dark
Activate this function if tampering associated with covering the lens (for instance, by spraying
paint on it) should trigger an alarm. The average brightness of the scene provides a basis for
recognition.
i
NOTICE!
The options for tamper detection can only be set for fixed cameras. Dome cameras or other
motorized cameras cannot be protected in this manner as the movement of the camera itself
causes changes in the video image that are too great.
i
NOTICE!
This and the following parameter are only accessible if the reference check is activated.