System, method and computer program for vote tabulation with an electronic audit trail

A method for determining votes recorded on a voter marked paper ballot, comprising:

• receiving, at a ballot processing computer, optical image data comprising an optical image of a voter-marked paper ballot, the optical image of the voter-marked paper ballot including identified voter selection areas;
• performing a pixel count of at least one voter selection area, the pixel count identifying a number of pixels in the optical image that contain a voter marking;
• determining, at the ballot processing computer, that one or more voter selection areas of the optical image of the voter-marked paper ballot have been selected when the pixel count of one or more of the identified voter selection areas in the optical image of the voter-marked paper ballot meet or exceed a predefined first threshold value for determining a specific voter selection area has been selected;
• determining, at the ballot processing computer, that one or more voter selection areas of the optical image of the voter-marked paper ballot have not been selected when the pixel count of one or more of the identified voter selection areas in the optical image of the voter-marked paper ballot fall at or below a predefined second threshold value for determining a specific voter selection area has not been selected;
• determining, at the ballot processing computer based at least in part on the pixel count, that the optical image of the voter-marked paper ballot includes at least one ambiguous mark when the pixel count of one or more of the identified voter selection areas in the optical image of the voter-marked paper ballot fall between the predefined first threshold value and second threshold value;
• and
• outputting, from the ballot processing computer, an indication that one or more of the identified voter selection areas are ambiguous when it is determined that the optical image of the voter-marked paper ballot includes at least one ambiguous mark.