Coding pattern comprising registration codeword having variants corresponding to possible registrations

摘要

A substrate having a coding pattern disposed thereon or therein. The coding pattern comprises a tiling of contiguous grid cells, each grid cell being demarcated by t target elements and having t-fold rotational symmetry, each grid cell containing nt registration symbols, each registration symbol being encoded by a set of macrodots; and a tiling of contiguous tags, each tag consisting of an array of c grid cells, each tag containing a plurality of data symbols. There are ct possible registrations between a physical layout of the coding pattern and a logical layout of the coding pattern and any contiguous tag-shaped array of c grid cells contains cnt registration symbols. The registration symbols, taken in a defined sequence relative to the physical layout of the tag-shaped array, form a registration codeword of length r. There are v distinct registration codewords, each corresponding to a distinct one of the ct possible registrations.