A marker detecting section detects markers formed at four corners of a block using binary image data of a two-dimensional code stored in a data memory. A marker's approximate center calculating section calculates the approximate centers of the detected markers. A pattern code detecting means detects...http://www.google.de/patents/US5860679?utm_source=gb-gplus-sharePatent US5860679 - Information recording medium, two-dimensional code, information reproduction system and information reproduction method
