To print a code to be read by a machine as well as information to be read by a user on a limited print surface with efficiency. An ID pattern is defined in a frequency domain and is transformed through an inverse Fourier transform. As a result of the inverse Fourier transform, the ID pattern becomes a pattern (ID background image) dispersed across a screen. In the printing apparatus according to the present invention, the ID background image is set as a background image, on which human-readable information composed of characters, images (designs), and/or the like are printed. Even thought the ID background image is lost, in a portion in which the human-readable information printed, it is possible to restore the ID pattern by Fourier-transforming the pattern in a remaining portion of the ID background image. A print medium, on which the human-readable information is printed with the ID background image as a background, is photographed with a camera provided for a mobile telephone, and photographed image data is transmitted from the mobile telephone to a URL server apparatus. The URL server receives the photographed image data from the mobile telephone, to subject the data to the Fourier transform, to thereby extract the ID pattern therefrom.