Substrate having coding pattern encoding reed-solomon symbols

Abstract

A substrate has a coding pattern printed on a surface thereof. The coding pattern encodes a plurality of Reed-Solomon symbols. Any one symbol has a value represented by m macrodots distributed amongst p possible positions within the symbol. The positions of the m macrodots amongst the p possible positions determines the value of the Reed-Solomon symbol. The macrodots of a first symbol that is adjacent to a second symbol are distributed such that the macrodots of the first symbol are not adjacent to the macrodots of the second symbol.

1 . A substrate having a coding pattern printed on a surface thereof, said coding pattern encoding a plurality of Reed-Solomon symbols, any one symbol having a value represented by m macrodots distributed amongst p possible positions within the symbol, the positions of said m macrodots amongst the p possible positions determining the value of the Reed-Solomon symbol, wherein the macrodots of a first symbol that is adjacent to a second symbol are distributed such that the macrodots of the first symbol are not adjacent to the macrodots of the second symbol. 
     
     
         2 . A substrate according to  claim 1 , wherein the m macrodots and p positions define a set of q unique values representable by each symbol, each of the q values represented by the same number of macrodots. 
     
     
         3 . The substrate of  claim 1 , wherein m is an integer of 2 or more and p>m. 
     
     
         4 . The substrate of  claim 1 , wherein m is 2 or 3. 
     
     
         5 . The substrate of  claim 1 , wherein said coding pattern comprises a plurality of target elements defining a target grid, said target grid comprising a plurality of cells. 
     
     
         6 . The substrate of  claim 4 , wherein each cell comprises one or more of said symbols. 
     
     
         7 . The substrate of  claim 1 , wherein said coding pattern comprises a plurality of Reed-Solomon codewords, each codeword comprising a plurality of said symbols. 
     
     
         8 . The substrate of  claim 7 , wherein a coordinate location is encoded by one or more of said Reed-Solomon codewords. 
     
     
         9 . The substrate of  claim 7 , wherein an identity of the substrate is encoded by one or more of said Reed-Solomon codewords.