Coding and decoding methods and apparatuses

An apparatus for generating a combined position and information code to be applied on a base, said code including a plurality of coding marks, each of which is displaced from one of a plurality of nominal positions defined by a grid, comprising:

• a memory device storing instructions;
• and
• a processor executing the instructions for:
• generating an electronic representation of a position code, which codes a plurality of positions, each position being coded by a first predetermined number of coding marks;
• assigning a graphical state value to each one of said plurality of coding marks in order to encode said plurality of positions, said graphical state value indicating a direction in which the coding mark is to be displaced from a corresponding nominal position when the coding mark is applied on the base;
• overlaying an electronic representation of an information code on the position code to create the combined code, said information code coding at least one information item by using a second predetermined number of coding marks;
• and
• selectively modifying the graphical state value of at least one of the second predetermined number of coding marks to encode the information item, wherein the modified graphical state value indicates that the coding mark is to be applied on the base with a size of the displacement from the corresponding nominal position that is different from the size of the displacement of the coding marks having unmodified graphical state values.

A method for decoding a combined position and information code, said code including a plurality of coding marks, each of which is displaced from one of a plurality of nominal positions defined by a grid, comprising:

• receiving an electronic representation of a part of said combined position and information code such that a part of information code is overlaid on a part of position code in the combined code;
• localizing coding marks in said electronic representation;
• identifying the grid;
• determining a direction of displacement from one of the nominal positions of the localized coding marks;
• decoding a position on the basis of the directions of displacements of a first predetermined number of the localized coding marks;
• determining an amount of displacement between one of the nominal positions and each one of a second predetermined number of the localized coding marks;
• and
• decoding an information item on the basis of the amounts of displacements of said second predetermined number of coding marks, wherein a coding mark having an amount of displacement of a first size is decoded to a first value and a coding mark having an amount of displacement of a second size is decoded to a second value.

An apparatus for decoding a combined position and information code, said code including a plurality of coding marks, each of which is displaced from one of a plurality of nominal positions defined by a grid, comprising;

• a memory device storing instructions;
• and
• a processor executing the instructions for:
• receiving an electronic representation of a part of said combined position and information code such that a part of information code is overlaid on a part of position code in the combined code;
• localizing a coding mark in said electronic representation;
• identifying the grid;
• determining a direction of displacement from one of the nominal positions of the localized coding marks;
• decoding a position on the basis of the directions of displacements of a first predetermined number of the localized coding marks;
• determining an amount of displacement between one of the nominal positions and each one of a second predetermined number of the localized coding marks;
• and
• decoding an information item on the basis of the amounts of displacements of said second predetermined number of coding marks, wherein a coding mark having an amount of displacement of a first size is decoded to a first value and a coding mark having an amount of displacement of a second size is decoded to a second value.