An image processing apparatus of the present invention includes: a self-similar image storing section 13 that stores a pattern of a self-similar image; a superimposed image data generating section 15 that generates superimposed image data from a self-similar image, based on the pattern of the self-similar image; an image combining section 17 that combines original image data with the superimposed image data; and a control section 11 that controls operations of the above-mentioned sections. The superimposed image data generating section 15 adjusts a pattern of a self-similar image so that a size of a superimposed image corresponds to a draw size of an original image which draw size is determined by the control section 11. It is therefore possible to combine the original image data with the superimposed image data so that the superimposed image is suitably drawn regardless of the draw size of the original image.