the person extraction unit determines whether or not each person detected in the moving image data to be analyzed appears in each of the plurality of pieces of child data, and calculates an appearance frequency for each detected person based on a result of the determination.

18-4. The program described in 18-2,

in which the moving image data to be analyzed includes moving image data captured at the same place over a predetermined time period, and

the person extraction unit analyzes the moving image data to be analyzed in units of time windows, each time window having a time width smaller than the predetermined time period, determines whether or not each person detected in the moving image data to be analyzed appears in each of a plurality of the time windows, and calculates an appearance frequency of each detected person based on a determination result.

18-5. The program described in 18-4, further causing the computer to function as an input receiving unit that receives a user input to set a time width of the time window.

18-6. The program described in 18-4, further causing the computer to function as an input receiving unit that receives a user input to individually set a start position and an end position of each of a plurality of the time windows.

18-7. The program described in any one of 18-2 to 18-6, in which the person extraction unit extracts a predetermined number of persons in descending order of appearance frequency.

18-8. The program described in any one of 18-2 to 18-6, in which the person extraction unit extracts a person whose appearance frequency is equal to or higher than a predetermined level.