摘要 |
A machine readable code comprises at least a portion of a graphical indicium, the graphical indicium comprising a random arrangement of spots. At least some of the spots comprising the graphical indicium may have a dimension of less than one micrometre. The spots comprising the graphical indicium may vary in size and/or shape. The portion of the graphical indicium comprising the code may be delimited by a boundary, the boundary may be a temporary boundary which may be generated by a reading machine relative to a fixed trigger point only when the code is being read. Alternatively, the portion of the graphical indicium comprising the code may be delimited by a graphically represented boundary. |