1. An information processing apparatus comprising: a storage unit which stores person relationship information representing the relationship between multiple people as a subject in a storage medium; an acquisition unit which acquires image data generated by imaging people as a subject; a detection unit which detects each person in an image based on image data acquired by the acquisition unit; a specification unit which specifies each person detected from the image by the detection unit; and a determination unit which determines the relationship between the multiple people detected from the image by the detection unit, wherein, when at least one person from among the multiple people detected from the image by the detection unit is specified and another person is unable to be specified, the specification unit specifies another person on the basis of the relationship between the multiple people determined by the determination unit and the person relationship information stored in the storage medium.