A printing medium that is capable of expressing vivid colors without increasing the number of colors and capable of suppressing a printing cost of a dot pattern printing, an information processing method, and an information processing device that use the printing medium are provided that make it possible to perform superposed printing of a graphic and a dot pattern with one color without using inks having different frequency characteristics. A dot pattern includes grid dots arranged in accordance with a predetermined rule for defining information with halftone dots that are superimposed and printed. The printing medium is printed in a way in which dots on the printing medium are detected from brightness information recorded in bitmap image data by a predetermined method and the dots are determined either as the grid dots that constitute the dot pattern or the halftone dots by an image analysis processing unit.