1. An augmented reality system including a recognition system and a book, the book comprising: a first page on a first leaf of the book comprising a first fiduciary marker for indicating an orientation of the book to the recognition system; a second page on a second leaf of the book comprising a second fiduciary marker and also a page marker for indicating a page number of the second page to the recognition system; wherein: an orientation of the page marker is ambiguous without reference to a fiduciary marker; and the page marker is positioned closer to an edge of the second page than the second fiduciary marker, so as to become visible to the recognition system before the second fiduciary marker as the book is turned to the second page; in which: the page marker encodes the page number as bits, comprising a most significant bit and a least significant bit, and the page marker comprises a pattern in which the least significant bit of the pattern is positioned to become visible to the recognition system before the most significant bit of the pattern as the book is turned to the second page; and the recognition system including a page marker recognition processor configured to recognize the page marker printed on the second page of the book with reference to the estimated orientation of the book as based upon the recognized first fiduciary marker printed on the first page of the book.