1. An image forming apparatus comprising: an image reading unit which reads an image; a photographing unit which photographs an image of at least one part other than a face of a whole body of a user who prints an image; a storing unit which stores data of the image of at least one part other than the face of the whole body of the user photographed by the photographing unit; a printing unit which forms an image including the data of the image of at least one part other than the face of the whole body of the user photographed by the photographing unit, and then prints the image on paper; a detecting unit which detects that printed paper, which is printed by the printing unit, is untaken; a notifying unit which, when the detecting unit detects untaken printed paper, notifies a user to promote reading of the image of the untaken printed paper by the image reading unit; an extracting unit which extracts the data of the image of at least one part other than the face of the whole body of the user photographed by the photographing unit from the image of the printed read by the image reading unit; and a displaying unit which displays the image of at least one part other than the face of the whole body of the user extracted by the extracting unit.