Questionnaire scanning system employing expandable answer mark areas for efficient scanning and mark detection
First Claim
1. A system for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
- image scanning means for initializing an unmarked questionnaire by scanning each unmarked page to create a pixel map thereof;
selecting means for defining selecting alignment points at one or more locations on each said page and detectible on said pixel map;
means for defining, on each said unmarked page, at least one area of interest within which is located an answer mark area location;
means for storing alignment point identifying data and area of interest location data;
said image scanning means including means for scanning a marked, completed questionnaire page for answer marks thereon and creating a pixel map of said completed page;
location means for locating the alignment points on said completed page pixel map;
comparator means for comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points;
location adjustment means for correcting said area of interest location data by applying said alignment point shift to thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; and
image differencing means, employing said adjusted stored locations of said areas of interest, for subtracting data of the stored areas of interest of the unmarked page pixel map from the data of the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks.
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Accused Products
Abstract
Questionnaires are scanned for answers(marks) handmarked thereon by defining areas of interest which can be expanded in an area of interest pixel map. An unmarked questionnaire is initialized by scanning to create a pixel map of an original image area, with any printed objects or text on the page being selected as alignment and reference points, rather than requiring timing marks and special registration marks. Areas of interest are defined answer area locations with their original pixel data stored in an initial database. Questionnaire pages are scanned for new answer images thereon by aligning both the page and the individual answer areas, and comparing the scanned page with the stored, unmarked page pixel map, thereby removing the pre-printed area from the newly scanned area to detect any new answers.
156 Citations
16 Claims
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1. A system for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
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image scanning means for initializing an unmarked questionnaire by scanning each unmarked page to create a pixel map thereof; selecting means for defining selecting alignment points at one or more locations on each said page and detectible on said pixel map; means for defining, on each said unmarked page, at least one area of interest within which is located an answer mark area location; means for storing alignment point identifying data and area of interest location data; said image scanning means including means for scanning a marked, completed questionnaire page for answer marks thereon and creating a pixel map of said completed page; location means for locating the alignment points on said completed page pixel map; comparator means for comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points; location adjustment means for correcting said area of interest location data by applying said alignment point shift to thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; and image differencing means, employing said adjusted stored locations of said areas of interest, for subtracting data of the stored areas of interest of the unmarked page pixel map from the data of the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
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image scanning means for initializing an unmarked questionnaire by scanning each unmarked page to create a pixel map thereof; selecting means for defining selecting alignment points at one or more locations on each said page and detectible on said pixel map; means for defining, on each said unmarked page, at least one area of interest within which is located an answer mark area location; means for storing alignment point identifying data and area of interest location data; said image scanning means including means for scanning a marked, completed questionnaire page for answer marks thereon and creating a pixel map of said completed page; location means for locating the alignment points on said completed page pixel map; comparator means for comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points; first location adjustment means for correcting said area of interest location data by applying said alignment point shift to thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; image shifting means including gating means for floating the area of interest pixel map of the unmarked page around the location of the area of interest pixel map of said completed page to overlay the pixel maps and determine the best fit, and, thus, the best fit area of interest location on said pixel map; second location adjusting means for applying said best fit area of interest location to said first location adjustment means to provide a fine adjustment of the stored location of the area of interest on the scanned completed page, thereby enabling more accurate detection of answer marks in said areas of interest, and image differencing means, employing said coarsely adjusted and said finely adjusted stored locations of said areas of interest, for subtracting data of the stored areas of interest of the unmarked page pixel map from the data of the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks.
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8. A system for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
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image scanning means for initializing an unmarked questionnaire by scanning each unmarked page to create a pixel map thereof; selecting means for defining selecting alignment points at one or more locations on each said page and detectible on said pixel map; means for defining, on each said unmarked page, at least one area of interest within which is located an answer mark area location; means for storing alignment point identifying data and area of interest location data; said image scanning means including means for scanning a marked, completed questionnaire page for answer marks thereon and creating a pixel map of said completed page; location means for locating the alignment points on said completed page pixel map; comparator means for comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points; location adjustment means for correcting said area of interest location data by applying said alignment point shift to thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; and image differencing means, employing said adjusted stored locations of said areas of interest, for subtracting data of the stored areas of interest of the unmarked page pixel map from the data of the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks, said image differencing means including gating means for expanding the pixel map areas around the preprinted data in said area of interest of said unmarked page by a predetermined amount and number of pixels so that a thickened area around said preprinted data is removed by said image differencing means and not mistakenly detected as an answer mark.
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9. A system for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
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image scanning means for initializing an unmarked questionnaire by scanning each unmarked page to create a pixel map thereof; selecting means for defining selecting alignment points at one or more locations on each said page and detectible on said pixel map; means for defining, on each said unmarked page, at least one area of interest within which is located an answer mark area location; means for storing alignment point identifying data and area of interest location data; said image scanning means including means for scanning a marked, completed questionnaire page for answer marks thereon and creating a pixel map of said completed page; location means for locating the alignment points on said completed page pixel map; comparator means for comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points; location adjustment means for correcting said area of interest location data including means for identifying areas of interest with corresponding individual alignment points located the closest thereto on said unmarked page, and means for applying said alignment point shift of the closest alignment point to correct the corresponding stored area of interest location data and thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; and image differencing means, employing said adjusted stored Iocations of said areas of interest, for subtracting data of the stored areas of interest of the unmarked page pixel map from the data of the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks.
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10. A system for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
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image scanning means for initializing an unmarked questionnaire by scanning each unmarked page to create a pixel map thereof; selecting means for defining selecting alignment points at one or more locations on each said page and detectible on said pixel map; means for defining, on each said unmarked page, at least one area of interest within which is located an answer mark area location; means for storing alignment point identifying data and area of interest location data; said image scanning means including means for scanning a marked, completed questionnaire page for answer marks thereon and creating a pixel map of said completed page; location means for locating the alignment points on said completed page pixel map; comparator means for comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points; location adjustment means for correcting said area of interest location data by applying said alignment point shift to thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; image differencing means, employing said adjusted stored locations of said areas of interest, for subtracting data of the stored areas of interest of the unmarked page pixel map from the data of the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks; a user defined database for defining, for each type of question on a questionnaire, the types and criteria for marks to be output as answers, wherein, based on the type of question, selected output processing will be employed for the mark; and answer output processing means for taking said answer marks, and applying said question definitions, from said user defined database, to said answer marks, and removing unwanted answer marks, thereby outputting said defined answers.
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11. A method for scanning a questionnaire for answer marks written thereon, said questionnaire comprised of at least one page having preprinted data thereon, comprising:
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initializing an unmarked questionnaire by image scanning each unmarked page to create a pixel map thereof, selecting a plurality of alignment points at different locations on said page and detectible on said pixel map, defining, on said unmarked page, at least one area of interest within which is located an answer mark area location ,and storing alignment point identifying data, an area of interest pixel map and area of interest location data; image scanning a completed questionnaire page for answer marks thereon and creating a pixel map of said completed page; locating the alignment points on said completed page pixel map; comparing the locations of said alignment points of said completed page pixel map with the locations of corresponding alignment points of said unmarked page pixel map to determine an alignment point shift required to correct for positional offset of the completed page from the unmarked page and true positions of the stored alignment points; correcting said area of interest location data by applying said alignment point shift to thereby provide a coarse adjustment of the stored locations of areas of interest to their new positions on the scanned completed pages; and image differencing the stored areas of interest of the unmarked page pixel map with the areas of interest of the scanned completed page pixel map to remove the common preprinted areas from the scanned completed page to detect any new answer marks. - View Dependent Claims (12, 13, 14, 15, 16)
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Specification