System and method for encoding and decoding data and position information using angular symbology and beacons

Method for use in decoding position information and reference orientation information encoded in at least one portion of an image, the at least one portion including a plurality of image elements, the method comprising:

• determining in a coded pattern in the elements a reference modulation pattern that is associated with a reference angular orientation and a reference frequency and defines a reference axis;
• determining in the coded pattern two or more position modulation patterns that are associated with one or more frequencies and are radially symmetric about respective position center points, the position modulation patterns having in the at least one portion respective angular orientations that correspond to offsets between the respective position center points and a center of the reference axis in the at least one portion;
• and
• determining the relative position of the at least one portion based on the reference orientation and the angular orientations.

An image in which is encoded position-related information, the image including:

• at least one portion including a plurality of image elements, and
• a characteristic of the elements which is modulated to include a coded modulation pattern, the coded modulation pattern including contributions of
• i. a reference elemental component having a reference angular orientation and a reference frequency and defining a reference axis in the at least one portion, and
• ii. two or more position components having one or more frequencies, each position component also having an angular orientation that corresponds to an offset between a center of the reference axis and an associated position center point.

Apparatus for use in encoding position beacons in at least one portion of an image, the at least one portion including a plurality of image elements, the apparatus including:

• a position information encoder that associates one or more position beacons with respective position modulation patterns in the elements, the position modulation patterns being radially symmetrical about respective center points that have predetermined locations in the image;
• an angular symbology encoder that associates a reference axis with a reference modulation pattern in the elements;
• and
• a processor that encodes the plurality of elements by combining the position modulation patterns and the reference modulation pattern to determine a coded pattern that represents changes to a characteristic of the plurality of the elements to encode the position information in the plurality of the elements.

Computer-readable memory comprising computer-executable program instructions for use in encoding position-related information in at least one portion of an image, the at least one portion including a plurality of image elements, the instructions, when executed, causing:

• determining a reference modulation pattern to be applied to a characteristic of the elements, the reference modulation pattern having a reference angular orientation and a reference frequency;
• determining at least two position modulation patterns having the same or different frequencies, the position modulation patterns being radially symmetrical about respective center points having predetermined locations;
• and
• modifying the characteristic of the image elements in accordance with a coded pattern that is a combination of the reference modulation pattern and the position modulation patterns.

Computer-readable memory comprising computer-executable program instructions for use in decoding position-related information encoded in at least one portion of an image, the at least one portion including a plurality of image elements, the instructions, when executed, causing:

• determining in a coded pattern in the elements a reference modulation pattern that is associated with a reference angular orientation and a reference frequency and defines a reference axis;
• determining in the coded pattern two or more position modulation patterns that are associated with one or more frequencies and are radially symmetrical about respective position center points having predetermined locations, the position modulation patterns having in the at least one portion respective angular orientations relative to the reference angular orientation that correspond to offsets between the respective position center points and a center of the reference axis;
• and
• determining the relative position of the at least one portion based on the angular orientations.