When a history including printed information, a date, a user, and the like is stored, a search for stored information is allowed, and the history can be referred to if information has leaked, a large-capacity storage device is required to store all images in the storage device. Hence, user authorization is made. If user authorization has succeeded, image data is acquired, and is segmented into regions of respective attributes by block selection. Next, objects of respective segments are converted into vector data. It is searched if an object that matches each of the objects is stored in an image storage server. If a matching object is detected, an object ID added to that object is acquired. If no matching object is detected, an object ID of the object of interest is generated, and vector data added with the object ID is registered in the image storage server.