Patent ID: 7999798

Claim:
A method of coding positions in two dimensions on a surface, comprising: coding positions along an x-axis using a first difference number sequence having the property that each partial sequence of a predetermined length has an unambiguously determined place within the first difference number sequence, each position along the x-axis being coded by one of said partial sequences, coding positions a long a y-axis using a second difference number sequence having the property that each partial sequence of a predetermined length has an unambiguously determined place within the second difference number sequence, each position along the y-axis being coded by one of said partial sequences, coding the numbers of the first difference number sequence by differences in circular shifts between instances of a first main number sequence running orthogonally to the first difference number sequence; and coding the numbers of the second difference number sequence by differences in circular shifts between instances of a second main number sequence running orthogonally to the second difference sequence.