the person extraction step includes analyzing the moving image data in units of time windows, each time window having a time width smaller than the predetermined time period, determining whether or not each person detected in the analyzed moving image data appears in each of a plurality of the time windows, and calculating an appearance frequency of each person based on a determination result.

17-5. The data processing method described in 17-4, further causing the computer to execute an input receiving step of receiving a user input to set a time width of the time window.

17-6. The data processing method described in 17-4, further causing the computer to execute an input receiving step of receiving a user input to individually set a start position and an end position of each of a plurality of the time windows.

17-7. The data processing method described in any one of 17-2 to 17-6, in which the person extraction step includes extracting a predetermined number of persons in descending order of appearance frequency.

17-8. The data processing method described in any one of 17-2 to 17-6, in which the person extraction step includes extracting a person whose appearance frequency is equal to or higher than a predetermined level.

17-9. The data processing method described in any one of 17-2 to 17-8, in which the output step includes outputting an image of the person acquired from the moving image data to be analyzed as information regarding the extracted person.

17-10. The data processing method described in 17-9, in which the output step includes displaying a list of a plurality of images of the person acquired from a plurality of different frames as information regarding the extracted person.