An image forming apparatus for forming a code pattern image, which includes position-dependent information differing at every position and position-independent information in common at various positions, the image forming apparatus includes: a position-dependent code storage section that stores a position-dependent code, in which position-dependent information corresponding to each position is encoded, or a position-dependent code image, in which a position-dependent code is expressed as an image code; a code pattern image generator that generates a code pattern image by combining a position-dependent code image at each position obtained on the basis of information stored in the position-dependent code storage section and a position-independent code image representing position-independent information; and an image forming section that forms, onto a surface of a medium, the pattern code image that is generated by the code pattern image generator.