In a PC, image data, position data indicating the position of the image data, and addition data associated with the image data are created. Further, the PC requests a background management unit to send a background pattern used to specify paper and a position on the paper, and prints the background pattern together with the image data. Further, the PC registers the background pattern, the addition data, and the position data in an information server in association with each other. When the user points to an image on the paper provided as the result of printing with a handwrite input pen, the background pattern and the pointing position are detected on the paper, and the addition data corresponding to the paper and the position is output.