Decoding and error correction in 2-D arrays

• US 7,330,605 B2
• Filed: 09/06/2006
• Issued: 02/12/2008
• Est. Priority Date: 10/31/2002
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Lin, Zhou Chen, Li, Yue, Wang, Jian
• Primary Examiner(s): PATEL, KANJIBHAI B
• Application Number:
  US11/470,334
• Publication Number:
  US 20070025641A1
• Time in Patent Office: 524 Days
• Field of Search: 382/224, 382/276, 382/291, 382/293, 382/305, 382/312, 345/166, 345180-183, 345/644
• US Class Current: 382/291
• CPC Class Codes: G06F 3/0321 by optically sensing the absolute position with respect to a regularly patterned surface forming a passive digitiser, e.g. pen optically detecting position indicative tags printed on a paper sheet constructional details of pen-shaped pointing devices G06F3/03545, G06F3/03542, G06F3/037
• CPC Class Codes: G06F 3/03545 Pens or stylus

Abstract

A system and process for determining the location of a captured image from a larger image is described. A non-repeating sequence may be folded into a non-repeating array in which the array is unique for every sub window of a given size. The image of the sub window may be captured and its location determined within the non-repeating array.

Claims

1. A process for determining a location in a sequence of a captured image comprising:

capturing an image with a camera from an electronic pen;

receiving a data stream corresponding to the captured image;

extracting columns from said captured image;

constructing a matrix from said columns;

sorting extracted code from said columns by distance;

determining a vector from said code to code in a larger array;

determining a position of the extracted code; and

determining a position of a tip of the electronic pen based upon the determined position of the extracted code.

2. The process according to claim 1, further comprising:

constructing at least another matrix from said columns; and

determining at least a second vector from said code.

3. The process according to claim 1, further comprising:

performing error correction on said code.

4. The process according to claim 1, further comprising:

outputting the determined position of the tip of the electronic pen to a display screen.

5. A computer-readable medium having program stored thereon for determining a location in a sequence of a captured image that, when executed by a computer causes the computer to:

capture an image with a camera from an electronic pen;

receive a data stream corresponding to the captured image;

extract columns from said captured image;

sort extracted code from said columns by distance;

construct a matrix from said columns;

determine a vector from said code to code in a larger array;

determine a position of the extracted code; and

determine a position of a tip of the electronic pen based upon the determined position of the extracted code.

6. The computer-readable medium according to claim 5, further causing the computer to:

construct at least another matrix from said columns; and

determine at least a second vector from said code.

7. The computer-readable medium according to claim 5, further causing the computer to:

perform error correction on said code.

8. The computer-readable medium according to claim 5, further causing the computer to:

output the determined position of the tip of the electronic pen to a display screen.

9. A system for determining a location of a captured image in a larger array to determine the position of a tip of an electronic pen with respect to a surface comprising:

a storage configured to store information regarding said larger array;

a camera in an electronic pen configured to capture an image;

an input configured to receive said captured image;

a processor configured to determine a distance between said captured image and said larger array by determining a shift of a sequential version of said captured image from said larger array and to determine a position of a tip of the electronic pen based upon the determined distance.

10. The system according to claim 9, the processor further configured to:

output the determined position of the tip of the electronic pen to a display screen.

11. The system according to claim 9, wherein the determined distance between said captured image and said larger array is a Hamming distance.