Left object detection device and left object detection method

A left object detection method for detecting an object left behind in a monitoring target area, comprising:

• a first step in which an acquisition section acquires an image of the area from an image pickup device for picking up an image of the monitoring target area;
• a second step in which upon detection of the object which has been kept static for a given time period as an article from the image acquired by the acquisition section, the processing section starts a timer for counting time from detection of the article, determines whether or not a person who owned the article matches a person in the image acquired by the acquisition section, stops the timer upon determination that they match, and does not stop the timer upon determination that they do not match;
• and
• a third step in which an output section outputs in accordance with a result of the processing section, wherein:
• the processing section determines whether or not the timer counts in excess of a predetermined time period;
• and
• upon determination made by the processing section that the timer counts in excess of the predetermined time period, the output section outputs an existence of the left object,
• the processing section regularly receives information about an act of leaving behind from an external system, and sets the predetermined time period in accordance with the received information, and
• upon reception of information indicating a vehicle operation interval from the external system, the processing section sets the predetermined time period to be longer as the operation interval of the received information becomes longer.