Patent US 9,400,951

To realize a dot pattern which can be read even by a frame buffer of which algorithm for search is simple and of which resolution is low without sacrificing an information dot for defining a direction of a block. There is provided a dot pattern, wherein a plurality of reference points is provided in an area of a block having a predetermined information dot arranged thereon; a plurality of virtual reference points to be defined is arranged from the reference points (for example, a central point of a grid area); an information dot is arranged, of which information is defined by a distance and a direction from the virtual reference point; and at least the information dot at the predetermined position is made into a direction dot showing the direction of the block by a direction from the virtual reference point.