Decoding and error correction in 2-D arrays
View Patent ↗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.
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.