1. An information processor comprising: a detection unit detecting a photographic subject region of an image; a characteristic amount generation unit generating a characteristic amount including at least positional information of the photographic subject region for each of the detected photographic subject region; a combined characteristic amount generation unit generating a combined characteristic amount corresponding to the image by combining the characteristic amount generated for each of the photographic subject region; and an identification unit identifying a label corresponding to a combination of a photographic subject appearing in the image based on the generated combined characteristic amount.