73
ifm Vision Assistant O3M
UK
10.2 Applying filters
The setting of the filters depends on the application and the environment . The filters must be set
separately for each application . When setting the filters, several aspects must be considered .
When looking at the filtered data, there is scope for interpretation, for example, due to noisy pixels .
The combination of different filters increases the reliability . However, a slight degree of uncertainty
always remains .
10.2.1 Example of area monitoring
For a better understanding of the connections between filter and application, the application "area
monitoring" and possible uncertainties are explained as an example .
The application "area monitoring" is supposed to trigger an alarm if a person enters a specific area .
The filters "signal quality filter" and "noise reduction filter" are set to [low] / [weak] . For these settings,
there are not many uncertainties caused by noisy pixels .
The filter "soiling detection" is set to [high sensitivity] . With this setting, there are not many uncertainties
caused by fog, water or ice .
Possible uncertainties due to wrongly interpreted pixels are tolerable since the security staff can inspect
the situation .
10.3 Signal quality filter
The "Signal quality filter" can filter pixels of dark objects . This reduces the number of incorrect
measurements . It does not matter how far the pixels are away . Typical applications are:
●
Filtering image zones with dark objects
●
Filtering invalid pixels caused by fog
●
Filtering invalid pixels caused by very close objects (< 0 .5 m)
Dark objects are objects that reflect little light in the infrared range (850 nm) .
To the human eye, dark objects are often quite visible in the infrared range . How much light an
object reflects at 850 nm can be verified in the monitoring screen with the amplitude image (→ „6
Do not use the signal quality filter to track dark objects in the infrared range .
Depending on the setting, the filter works with low, medium or high sensitivity . The higher the sensitivity,
the more pixels are filtered and marked as invalid .
Test the ideal filter setting under difficult conditions:
●
strong sunlight
●
wet surfaces
