Reference Check - Bosch LTC-1311-20 Configuration Manual

Bosch Video Management System
trigger an alarm. Set a low value if changes that occur simultaneously in a large number of
areas should lead to trigger an alarm. This setting allows you to detect, independently of
motion alarms, manipulation of the orientation or location of a camera resulting from turning
the camera mount bracket.
This setting is independent of the areas selected in the Select Area window (see
Section 18.8.2 Select Area diaog box, page 118).
Scene too dark
Select the check box if covering the objective (for instance, by spraying paint on the
objective) should trigger an alarm. The average brightness of the scene provides a basis for
recognition.
Scene too noisy
Select the check box if EMC interferences (noisy scene as the result of a strong interference
signal) should trigger an alarm.
18.8.4

Reference check

Allows you to compare the current video image with the reference image that is stored.
If the current video image differs from the reference image in the marked areas, an alarm is
triggered. This function detects tampering that would otherwise not be detected, for example
if the camera is turned.
Enable
Select the check box to activate the reference check.
Select Area...
Click to configure the areas for tamper detection. The Select Area dialog box is displayed (see
Section 18.8.2 Select Area diaog box, page 118).
Set Reference
Click to save the currently visible video image as reference image.
Sensitivity
Move the slider to set the basic sensitivity of the tamper detector. The tamper detector 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.
Sensitivity can only be changed if Reference check is enabled.
Trigger delay (s)
Enter the time for delayed alarm triggering. The alarm is only triggered if the triggering
condition still exists after this time. if the triggering condition does not exist after this time,
the alarm is not triggered. The delay avoids false alarms triggered by short-term changes, for
example, cleaning activities in the direct field of vision of the camera.
Trigger delay (s) can only be changed if Reference check is enabled.
Edge check
Select an item from the list to specify the reference check.
Disappearing edges: The area selected in the reference image should contain a prominent
structure. If this structure is concealed or moved, the reference check triggers an alarm. If the
selected area is too homogenous, so that concealing and moving the structure would not
trigger an alarm, then an alarm is triggered immediately to indicate the inadequate reference
image.
Appearing edges: Select this option if the selected area of the reference image includes a
largely homogenous surface. If structures appear in this area, then an alarm is triggered.
Bosch Sicherheitssysteme GmbH Configuration Manual
Encoders / Decoders page | en 119
Configuration Client | V3 | 2010.07