METHOD OF DECODING CODING PATTERN HAVING SELF-ENCODED FORMAT

• US 20110182514A1
• Filed: 01/27/2010
• Published: 07/28/2011
• Est. Priority Date: 01/27/2010
• Status: Abandoned Application

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Napper, Johnathon Leigh, Lapstun, Paul
• Application Number:
  US12/694,263
• Publication Number:
  US 20110182514A1
• Time in Patent Office: Days
• US Class Current: 382/190
• CPC Class Codes: G06K 19/06037 multi-dimensional coding

Abstract

A method of decoding a coding pattern disposed on or in a substrate. The method comprises the steps of: (a) operatively positioning an optical reader relative to a surface of the substrate; (b) capturing an image of a portion of the coding pattern; (c) sampling and decoding a registration symbol contained in the imaged portion; (d) determining, using the decoded registration symbol, an encoding format; and (e) using the determined encoding format to sample and decode data symbols in the imaged portion. The coding pattern comprises a plurality of macrodots encoding data symbols and registration symbols, wherein each data symbol is represented by d macrodots, each of the d macrodots occupying a respective position from a plurality of predetermined possible positions p, the respective positions of the d macrodots representing one of a plurality of possible data values. Each registration symbol, or a set of the registration symbols, identifies an integer value of d and thereby the encoding format.

Claims

1. A method of decoding a coding pattern disposed on or in a substrate, said method comprising the steps of:

(a) operatively positioning an optical reader relative to a surface of said substrate;

(b) capturing an image of a portion of said coding pattern, said coding pattern comprising a plurality of macrodots encoding data symbols and registration symbols, wherein;

each data symbol is represented by d macrodots, each of said d macrodots occupying a respective position from a plurality of predetermined possible positions p, the respective positions of said d macrodots representing one of a plurality of possible data values;

each registration symbol, or a set of said registration symbols, identifies an integer value of d; and

p>

d,

(c) sampling and decoding at least one registration symbol contained in said imaged portion;

(d) determining, using the decoded registration symbol, the value of d; and

(e) using the determined value of d to sample and decode the data symbols in the imaged portion.

2. The method of claim 1, wherein said coding pattern has one of a plurality of different formats, each different format having a different value of d.

3. The method of claim 2, wherein said registration symbols are configured and positioned identically in each of said different formats.

4. The method of claim 2, wherein a first format of said coding pattern has a higher visibility than a second format of said coding pattern.

5. The method of claim 2, wherein d is an integer value of 2 to 6 and p is an integer value of 4 to 12, and wherein the value of p is fixed for each format of said coding pattern.

6. The method of claim 1, wherein each data symbol provides i possible symbol values for a j-bit symbol, and wherein (ĩ

2^j) unused symbol values are treated as erasures during decoding of said data symbols.

7. The method of claim 6, wherein said unused symbol values are selected to minimize clustering of macrodots between adjacent data symbols.

8. The method of claim 1, wherein said coding pattern further comprises a plurality of target elements defining a target grid, said targets elements being distinguishable from said macrodots.

9. The method of claim 8, wherein said coding pattern comprises a plurality of symbol groups, each symbol group comprising at least one target element, at least one registration symbol and a plurality of said data symbols.

10. The method of claim 9, wherein said coding pattern comprises a plurality of tags, each tag comprising a plurality of symbol groups, a plurality of registration symbols and a plurality of target elements.

11. The method of claim 10, wherein each symbol group comprises at least one set of registration symbols, said set identifying the integer value of d.

12. The method of claim 10, wherein each tag comprises at least one Reed-Solomon codeword comprised of a plurality of said data symbols.

13. The method of claim 12, wherein each tag comprises at least one local codeword identifying a location of a respective tag.

14. The method of claim 12, wherein each tag comprises one or more common codewords, each common codeword being common to a plurality of contiguous tags.

15. The method of claim 14, wherein said one or more common codewords identify a region identity, said region identity uniquely identifying said substrate or a region thereof.

16. The method of claim 1, wherein said registration symbols further identify:

a translation of a symbol group relative to a tag containing said symbol group, each symbol group containing a plurality of said data symbols.

17. The method of claim 16, further comprising the step of:

determining the translation of each symbol group using the decoded registration symbol; and

determining an alignment of a tag with said symbols groups using said translation.

18. The method of claim 1, wherein said registration symbols further identify one or more of:

an orientation of a layout of said data symbols with respect to a target grid; and

a flag.

19. A system for decoding a coding pattern, said system comprising:

(A) a substrate having a coding pattern disposed therein or therein, said coding pattern comprising a plurality of macrodots encoding data symbols and registration symbols, wherein;

each data symbol is represented by d macrodots, each of said d macrodots occupying a respective position from a plurality of predetermined possible positions p, the respective positions of said d macrodots representing one of a plurality of possible data values;

each registration symbol, or a set of said registration symbols, identifies an integer value of d; and

p>

d,

(B) an optical reader comprising;

an image sensor for capturing an image of a portion of said coding pattern; and

a processor configured for performing the steps of;

(i) sampling and decoding at least one registration symbol contained in said imaged portion;

(ii) determining, using the decoded registration symbol, the value of d; and

(iii) using the determined value of d to sample and decode the data symbols in the imaged portion.

20. An optical reader for decoding a coding pattern disposed on or in a substrate, said coding pattern comprising a plurality of macrodots encoding data symbols and registration symbols, wherein:

each data symbol is represented by d macrodots, each of said d macrodots occupying a respective position from a plurality of predetermined possible positions p, the respective positions of said d macrodots representing one of a plurality of possible data values;

each registration symbol, or a set of said registration symbols, identifies an integer value of d; and

p>

d,

said optical reader comprising;

an image sensor for capturing an image of a portion of either first or second coding pattern; and

a processor configured for performing the steps of;

(i) sampling and decoding at least one registration symbol contained in said imaged portion;

(ii) determining, using the decoded registration symbol, the value of d; and

(iii) using the determined value of d to sample and decode the data symbols in the imaged portion.