Patent ID: 8292190
Filing Date: 2012-10-23
Classification: G06K

Abstract:
1. A substrate having a coding pattern disposed thereon or therein, said coding pattern comprising: 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 and having an identical layout of data symbols, each data symbol being encoded by a set of macrodots; wherein: the coding pattern has a physical layout defined by its tiling of contiguous grid cells, said physical layout belonging to a plane symmetry group that has t-fold rotational symmetry and translational symmetry with the grid cell as its unit cell; the coding pattern has a logical layout defined by its tiling of contiguous tags, said logical layout belonging to a plane symmetry group that has no rotational symmetry but has translational symmetry with the tag as its unit cell; there are ct possible registrations between the physical layout of the coding pattern and the logical layout of the coding pattern, each registration corresponding to a distinct combination of one of the t possible rotations of the physical layout of coding pattern relative to the logical layout of the coding pattern and one of the c possible translations of the physical layout of the coding pattern relative to the logical layout of the coding pattern; any contiguous tag-shaped array of c grid cells contains cnt registration symbols, said registration symbols, taken in a defined sequence relative to the physical layout of the tag-shaped array, forming a registration codeword of length r; there are v distinct registration codewords, each corresponding to a distinct one of the ct possible registrations; the registration codeword of each contiguous tag-shaped array of c grid cells thereby uniquely identifies a registration between said tag-shaped array and the logical layout of the coding pattern; t=is an integer value of 2 or more; c=is an integer value of 2 or more; n is an integer value of 1 or more;