In addition, by displaying a list of a plurality of persons extracted by the person extraction unit 10 so as to be aligned in descending order of appearance frequency as shown in FIG. 9, it is possible to view a plurality of persons having high appearance frequencies together and to easily recognize the ranking easily.

By displaying a list of a plurality of face images acquired from a plurality of different frames in association with each of the plurality of persons extracted by the person extraction unit as shown in FIG. 9, it is possible to recognize the movement of the person. For example, it is possible to recognize whether the person lingering in the same place or is moving within a certain range, based on differences in the background, differences in the directions of the face, differences in brightness, and the like.

By checking whether or not face images of different persons are included in a plurality of face images acquired from a plurality of frames, it is possible to check the accuracy of the processing for grouping persons extracted from the plurality of frames such that the same person belongs to the same group. As described in the second example embodiment, in a case where the data processing apparatus 1 includes a “unit by which the user can set the criteria for similarity”, the user can adjust the criteria for similarity while checking the display shown in FIG. 9. As a result, persons extracted from a plurality of frames can be grouped with high accuracy such that the same person belongs to the same group.