One objective is to provide an image processing device, a control method, and a storage medium capable of suitably presenting information about a position currently being photographed in endoscopic inspection. To achieve the objective, the image processing device 1X includes a panoramic image acquiring unit 43X and a display control unit 46X. The panoramic image acquiring unit 43X acquires a panoramic image Ip, in which a wall surface in a lumen is expanded in a planar shape, based on plural captured images Ic which were acquired by photographing the lumen by a photographing unit provided in an endoscope in a first photographing process. The display control unit 46X displays on the display device 2 photographed position information relating to a photographed position of the lumen in a second photographing process in association with the panoramic image Ip.