Operation Manual

IVA 4.0 IVA 4.0 | en 31
Bosch Security Systems Operating Manual DOC | 4.0 | 2009.06
Next Step - Approximation
You can impose approximations for the different object properties. You can adopt these
values as the basis for the settings in the next step.
These settings are described here: Section Next Step - Approximation, page 24.
Next Step - Define the Conditions
You limit the number of objects that trigger an alarm event by precisely defining properties
such as size, aspect ratio, speed and direction.
These settings are described here: Section Next Step - Define the Conditions, page 25.
Note: Approximations cannot be used for the Crossing line task.
Next Step - Define the Color
You limit the number of objects that trigger an alarm event by defining the color properties
more precisely.
These settings are described here: Section Next Step - Define the Color, page 28.
Final Step - Define the Head Detection Conditions
In this step, you define whether an alarm should be triggered according to whether or not
detected objects have a head. This enables you to set the surveillance to focus on people or
exclude them completely.
These settings are described here: Section Final Step - Define the Head Detection Conditions,
page 29.
4.5.4 Loitering
This task generates an alarm event if an object only moves slightly within a certain area for a
specified period. The area is defined by a field in the camera image.
First Step - Define the Field
1. Select one of the fields.
To do this, use the list field or click a field in the camera image.
You can also create a new field, edit an existing one or select Whole screen.
2. Debounce time [s]
If a value other than 0 (zero) is selected, the alarm event will not be generated until the
object has moved or been within the field for the specified period at least.
By entering a value, you can prevent the triggering of multiple alarm events by objects
that are constantly moving toward and away from the boundary of the field.
Next Step - Define the Trigger
An alarm is generated if an object only moves within the tolerance area during a time span.
As soon as an object is detected in the sensitive area, a virtual circle corresponding to the
tolerance area is placed around the object. If the object does not leave this tolerance area
during the specified time and the object remains in the monitored field, an alarm is triggered.
If the object leaves the tolerance area during the specified time, a new virtual circle is defined
around the current position and the measurement of time starts again.
– Radius [m]
Here you can specify the size of the circle that the object must not leave for it to be
detected as loitering.
– Time [s]
This specifies the period of time in seconds during which the object must remain within
the virtual circle.