A method of imaging a coding pattern disposed on a surface of a substrate. The method comprises the steps of: (a) capturing an image of a portion of the coding pattern; and (b) low-pass filtering said captured image so as to obscure data elements and preserve target elements. The coding pattern comprises...http://www.google.com.au/patents/US8070071?utm_source=gb-gplus-sharePatent US8070071 - Method of imaging a coding pattern with data elements encoding by multi-pulse position modulation
