A device and method for detection of an event in a monitoring area. The detection device includes a camera interface for transferring at least one image of the monitoring area, an image analysis unit configured to determine event specifications for at least any one position in the monitoring area, an alarm unit configured to define an alarm based on a comparison of alarm specifications with the event specifications, a storage unit configured to store the event specifications for the at least any one position, a calculation unit configured to determine at least one false event area based on the event specifications and the alarm specifications, and a masking unit configured to automatically modify the alarm specifications within the at least one false event area, exclude the false event area from the determination of event specifications by the image analysis unit, or both.