An image signal output device includes a code generating means for generating a two-dimensional geometrical code based on a source data, a obtaining means for retrieving a sequential image signal, a code inserting means for inserting the two-dimensional geometrical code in the sequential image signal and a output means for outputting the sequential image signal. The code inserting means imperceptibly inserts the two-dimensional geometrical code in the sequential image signal, and the output means outputs the sequential image signal having the two-dimensional geometrical code inserted therein. The imperceptible two-dimensional geometrical code is captured by a camera in a cell phone to be decoded and stored in a memory medium.