Monitoring device and monitoring system

A monitoring device comprising a processor,

• wherein the processor is configured to:
• acquire a camera image, an image shot by a camera, of a no-entry zone, in which vehicles can travel, and a platform zone, in which passengers can board and exit vehicles;
• detect an intrusion of a person into the no-entry zone based on the camera image;
• and
• instruct the monitoring device to issue an alert of the person's intrusion,
• wherein the processor is further configured to:
• perform a first operation for detecting a person intruding from the platform zone into the no-entry zone based on the camera image;
• perform a second operation for determining whether or not a vehicle is present in the no-entry zone based on the camera image;
• and
• determine whether an alert needs to be issued or not based on a detection result of the first operation and a determination result of the second operation,
• wherein a region which the camera can shoot is determined as a shooting region of the camera, and
• wherein, when a deviation of the shooting region occurs such that a current shooting region deviates from an original shooting region, the processor performs an image conversion operation for converting a current camera image of the current shooting region to a converted camera image, which is an image that would be captured by the camera with the original shooting region, and uses the converted camera image as a basis for the first and second operations.