Decoding message data embedded in an image print via halftone dot orientation

A system for decoding data embedded in an image via halftone dot orientation, the system comprising:

• a storage medium capable of storing data;
• and
• a processor in communication with said storage medium, said processor capable of executing a machine readable instruction for performing the method of:
• scanning an image print containing a data message embedded therein, said message comprising a plurality of single data values, each single data value taking only one unique state;
• synchronizing said scanned image to a uniform periodic tiling utilized for generating said image print to compensate for geometric distortions introduced by print/scan processes performed on said image print;
• associating a unique orientation direction with each of said unique states, each of said unique orientation directions being oriented with respect to a horizontal and vertical axis of said scanned image print;
• defining a uniform periodic tiling for said scanned image;
• and
• for each of said uniform periodic tiles in said uniform tiling,
• calculating a plurality of image moments for a halftone dot of a current tile, one image moment being calculated along each of said unique orientation directions;
• determining a largest of said calculated moments, said largest moment identifying a dominant orientation direction for said halftone dot;
• and
• decoding a single data value embedded in said current tile based on which of said unique states is associated said determined dominant orientation direction.

A computer program product for decoding data embedded in an image via halftone dot orientation, the computer program product comprising:

• a non-transitory computer readable media for storing instructions that, when executed on a computer, cause the computer to perform a method comprising:
• scanning an image print containing a data message embedded therein, said message comprising a plurality of single data values, each single data value taking only one unique state;
• synchronizing said scanned image to a uniform periodic tiling utilized for generating said image print to compensate for geometric distortions introduced by print/scan processes performed on said image print;
• associating a unique orientation direction with each of said unique states, each of said unique orientation directions being oriented with respect to a horizontal and vertical axis of said scanned image print;
• defining a uniform periodic tiling for said scanned image;
• and
• for each of said uniform periodic tiles in said uniform tiling,
• calculating a plurality of image moments for a halftone dot of a current tile, one image moment being calculated along each of said unique orientation directions;
• determining a largest of said calculated moments, said largest moment identifying a dominant orientation direction for said halftone dot;
• and
• decoding a single data value embedded in said current tile based on which of said unique states is associated said determined dominant orientation direction.