System and method for decoding marks on a response sheet

• US 8,840,022 B1
• Filed: 08/13/2013
• Issued: 09/23/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Election Systems & Software Incorporated
• Original Assignee: Election Systems & Software Incorporated
• Inventors: Dvorak, Mike, Roger, Bruno
• Primary Examiner(s): Labaze, Edwyn
• Application Number:
  US13/965,368
• Publication Number:
  US 20140263637A1
• Time in Patent Office: 406 Days
• Field of Search: 235/386, 235/375, 235/51, 705/12, 705/14
• US Class Current: 235/386
• CPC Class Codes: G07C 13/00 Voting apparatus
• CPC Class Codes: G07C 13/02 Ballot boxes
• CPC Class Codes: H04N 1/00366 Marks in boxes or the like, e.g. crosses or blacking out H04N1/0036 takes precedence
• CPC Class Codes: H04N 1/00371 on a separate sheet
• CPC Class Codes: H04N 1/00376 Means for identifying a mark sheet or area
• CPC Class Codes: H04N 1/00379 Means for enabling correct scanning of a mark sheet or area, e.g. registration or timing marks
• CPC Class Codes: H04N 1/00968 by scanning marks on a sheet mark-sheet input means H04N1/00355; sensing record carriers G06K7/00

Abstract

A ballot tabulation device includes a scanner operable to obtain an image of at least a portion of a paper ballot that includes a voter response area. A processor applies a virtual template to the image to identify a center point for the voter response area. The virtual template comprises a set of characteristic points positioned in predetermined locations in relation to the center point of the voter response area, wherein the characteristic points comprise points that are common to a plurality of sample ballot images. The processor also defines a response window that is centered on the center point of the voter response area, and analyzes the response window to determine if the voter response area is marked by a voter.

Claims

1. A ballot tabulation device for analyzing one or more voter response areas on a paper ballot, comprising:

a scanner operable to obtain an image of at least a portion of the paper ballot that includes a voter response area;

a processor operable to analyze the image by;

identifying an initial reference point that approximates a location of a reference point for the voter response area;

determining the location of the reference point for the voter response area using the initial reference point and a virtual template applied to the image;

using the reference point for the voter response area to define a response window; and

analyzing the response window to determine if the voter response area is marked by a voter.

2. The ballot tabulation device of claim 1, wherein the reference point for the voter response area comprises a center point of the voter response area.

3. The ballot tabulation device of claim 2, wherein the response window comprises a rectangular window that is centered on the center point of the voter response area.

4. The ballot tabulation device of claim 1, wherein the voter response area includes a printed outline that defines an outer boundary of the voter response area.

5. The ballot tabulation device of claim 4, wherein the printed outline of the voter response area has an oval shape.

6. The ballot tabulation device of claim 4, wherein the virtual template comprises a set of characteristic points positioned in predetermined locations in relation to the reference point of the voter response area.

7. The ballot tabulation device of claim 6, wherein at least some of the characteristic points are located on the printed outline of the voter response area.

8. The ballot tabulation device of claim 1, wherein the paper ballot includes a left timing mark, a right timing mark, a top timing mark and a bottom timing mark associated with the voter response area, and wherein the initial reference point is identified by locating an intersection of a first virtual line connected between the left and right timing marks and a second virtual line connected between the top and bottom timing marks.

9. The ballot tabulation device of claim 1, wherein the virtual template comprises a set of characteristic points positioned in predetermined locations in relation to the reference point of the voter response area.

10. The ballot tabulation device of claim 9, wherein the processor is operable to overlay the characteristic points on the image in a position determined by the initial reference point and calculate a score corresponding to a number of the characteristic points that match corresponding points on the image.

11. The ballot tabulation device of claim 10, wherein the processor determines that the reference point is the initial reference point if the score associated with the initial reference point is above an upper threshold value.

12. The ballot tabulation device of claim 11, wherein the score associated with the initial reference point is below the upper threshold value, and wherein the processor is operable to:

identify one or more adjusted reference points located one or more distances from the initial reference point; and

for each of the adjusted reference points, overlay the characteristic points on the image in a position determined by the adjusted reference point and calculate a score corresponding to a number of the characteristic points that match corresponding points on the image.

13. The ballot tabulation device of claim 12, wherein the processor determines that the reference point is the one of the adjusted reference points associated with a score above the upper threshold value.

14. The ballot tabulation device of claim 12, wherein the score associated with each of the adjusted reference points is below the upper threshold value, and wherein the processor is operable to identify the initial reference point or the one of the adjusted reference points associated with the highest score.

15. The ballot tabulation device of claim 14, wherein the processor determines that the reference point is the initial reference point or the one of the adjusted reference points associated with the highest score if the highest score is above a lower threshold value.

16. The ballot tabulation device of claim 1, wherein the processor is operable to apply a virtual mask to the image to mask all points outside of the voter response area.

17. The ballot tabulation device of claim 16, wherein the voter response area includes a printed outline that defines an outer boundary of the voter response area, and wherein the virtual mask also masks the printed outline.

18. The ballot tabulation device of claim 1, wherein the virtual template comprises a set of characteristic points positioned in predetermined locations in relation to the reference point of the voter response area.

19. The ballot tabulation device of claim 18, wherein the characteristic points comprise points that are common to a plurality of sample images of a plurality of sample paper ballots.

20. The ballot tabulation device of claim 19, wherein the sample paper ballots are printed on a plurality of printers.

21. The ballot tabulation device of claim 19, wherein the sample paper ballots are scanned on a plurality of tabulation devices to obtain the sample images.

22. A system for analyzing one or more voter response areas on a paper ballot, comprising:

a scanner operable to obtain an image of at least a portion of the paper ballot that includes a voter response area, wherein the voter response area includes a printed outline that defines an outer boundary of the voter response area;

a processor operable to analyze the image by;

identifying an initial center point that approximates a location of a center point for the voter response area;

determining the location of the center point for the voter response area using the initial center point and a virtual template, wherein the virtual template comprises a set of characteristic points positioned in predetermined locations in relation to the center point of the voter response area;

defining a response window that is centered on the center point of the voter response area; and

analyzing the response window to determine if the voter response area is marked by a voter.

23. The system of claim 22, wherein at least some of the characteristic points are located on the printed outline of the voter response area.

24. The system of claim 22, wherein the paper ballot includes a left timing mark, a right timing mark, a top timing mark and a bottom timing mark associated with the voter response area, and wherein the initial center point is identified by locating an intersection of a first virtual line connected between the left and right timing marks and a second virtual line connected between the top and bottom timing marks.

25. The system of claim 22, wherein the processor is operable to apply a virtual mask to the image to mask the printed outline and all points outside of the voter response area.

26. The system of claim 22, wherein the characteristic points comprise points that are common to a plurality of sample images of a plurality of sample paper ballots.

27. The system of claim 26, wherein the sample paper ballots are printed on a plurality of printers.

28. The system of claim 26, wherein the sample paper ballots are scanned on a plurality of tabulation devices to obtain the sample images.

29. A system for analyzing one or more response areas on a response sheet, comprising:

a scanner operable to obtain an image of at least a portion of the response sheet that includes a response area;

a processor operable to analyze the image by;

identifying an initial reference point that approximates a location of a reference point for the response area;

determining the location of the reference point for the response area using the initial reference point and a virtual template, wherein the virtual template comprises a set of characteristic points positioned in predetermined locations in relation to the reference point of the response area;

using the reference point for the response area to define a response window; and

analyzing the response window to determine if the response area is marked.

30. The system of claim 29, wherein the reference point for the response area comprises a center point of the response area.

31. The system of claim 30, wherein the response window comprises a rectangular window that is centered on the center point of the response area.

32. The system of claim 29, wherein the response area includes a printed outline that defines an outer boundary of the response area.

33. The system of claim 32, wherein the printed outline of the response area has an oval shape.

34. The system of claim 32, wherein at least some of the characteristic points are located on the printed outline of the response area.

35. The system of claim 29, wherein the response sheet includes a left timing mark, a right timing mark, a top timing mark and a bottom timing mark associated with the response area, and wherein the initial reference point is identified by locating an intersection of a first virtual line connected between the left and right timing marks and a second virtual line connected between the top and bottom timing marks.

36. The system of claim 29, wherein the processor is operable to overlay the characteristic points on the image in a position determined by the initial reference point and calculate a score corresponding to a number of the characteristic points that match corresponding points on the image.

37. The system of claim 36, wherein the processor determines that the reference point is the initial reference point if the score associated with the initial reference point is above an upper threshold value.

38. The system of claim 37, wherein the score associated with the initial reference point is below the upper threshold value, and wherein the processor is operable to:

identify one or more adjusted reference points located one or more distances from the initial reference point; and

for each of the adjusted reference points, overlay the characteristic points on the image in a position determined by the adjusted reference point and calculate a score corresponding to a number of the characteristic points that match corresponding points on the image.

39. The system of claim 38, wherein the processor determines that the reference point is the one of the adjusted reference points associated with a score above the upper threshold value.

40. The system of claim 38, wherein the score associated with each of the adjusted reference points is below the upper threshold value, and wherein the processor is operable to identify the initial reference point or the one of the adjusted reference points associated with the highest score.

41. The system of claim 40, wherein the processor determines that the reference point is the initial reference point or the one of the adjusted reference points associated with the highest score if the highest score is above a lower threshold value.

42. The system of claim 29, wherein the processor is operable to apply a virtual mask to the image to mask all points outside of the response area.

43. The system of claim 42, wherein the response area includes a printed outline that defines an outer boundary of the response area, and wherein the virtual mask also masks the printed outline.

44. The system of claim 29, wherein the characteristic points comprise points that are common to a plurality of sample images of a plurality of response sheets.

45. The system of claim 44, wherein the sample response sheets are printed on a plurality of printers.

46. The system of claim 44, wherein the sample response sheets are scanned on a plurality of optical scanners to obtain the sample images.