Transaction document reader

• US 5,416,308 A
• Filed: 08/29/1991
• Issued: 05/16/1995
• Est. Priority Date: 08/29/1991
• Status: Expired due to Term

• Current Assignee: IGT (International Game Technology)
• Original Assignee: Video Lottery Technologies, Inc. (International Game Technology)
• Inventors: Petersen, Bruce L., Hood, Ernest J., Machnik, Patrick R., Selden, Joseph C.
• Primary Examiner(s): SHEPPERD, JOHN W
• Application Number:
  US07/751,771
• Time in Patent Office: 1,356 Days
• Field of Search: 235/456, 235/454, 382/61
• US Class Current: 235/454
• CPC Class Codes: G06K 17/0032 Apparatus for automatic testing and analysing marked record carriers, used for examinations of the multiple choice answer type teaching apparatus working with questions and answers G09B7/00
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/1444 Selective acquisition, locating or processing of specific regions, e.g. highlighted text, fiducial marks or predetermined fields
• CPC Class Codes: G06V 30/146 Aligning or centring of the image pick-up or image-field

Abstract

A transaction document reader reads image data on a transaction document. The image data includes marking areas employed by a user to record marks and includes characters. A sensor senses, one row at a time, rows of image data as the document is transported across the sensor. Each row includes a number of pixel areas. The pixel areas of the rows being aligned in columns. The sensor generates output signals representative of the pixel areas. The output signals are transformed into bit signals representative of each pixel area. The bit signals are stored in image memory which is organized into rows and columns of bit signals corresponding to the rows and columns of the pixel areas of the image data. The marking areas are located in image memory. The marks are identified in the marking areas while additional rows of bit signals are being stored and while other marking areas are being located by probing the bit signals in image memory. A specific area within image memory representative of a single character is also located. A neural network is utilized to recognize the character within specific area.

Claims

1. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel areas;

transform means for receiving said output signals and generating bit signals representative of each pixel area, wherein said transform means comprises means for digitizing said output signals representative of said pixel areas and for providing gray scale digitized output signals, transform memory means for generating and storing bit signals for individual columns as a function of a threshold value, and means for addressing said transform memory means to select a bit signal representative of whether the gray scale digitized output signals are representative of generally dark or light pixel areas;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory; and

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means.

2. An apparatus according to claim 1, wherein said means for addressing, comprises:

means for applying the gray scale digitized output signals representative of said pixel areas and bit position signals representative of the columns of said pixel areas to said transform memory means, on a pixel by pixel basis; and

means for selecting from said transform memory, in response to said means for applying, a bit signal for each of said gray scale digitized output signals representative of said pixel areas.

3. An apparatus according to claim 2, wherein said transform memory means comprises:

means for averaging a plurality of output signals representative of pixel areas in each column of pixel areas when a reflective card is transported across said sensor means and for generating an averaged output signal representative of said output signals;

means for applying a predetermined threshold percentage to the averaged output signal to determine a threshold value address; and

means for mapping said transform memory such that said transform memory contains a first bit signal at said threshold value address and at addresses higher than said threshold value address, and contains a second bit signal at addresses lower than said threshold value address.

4. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel areas;

transform means for receiving said output signals and generating bit signals representative of each pixel area;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, including means for identifying a type of transaction document by probing a predetermined plurality of rows of said image memory means in order to determine dimensions of said document, said type of document having certain dimensions; and

wherein said at least one portion of image memory means representative of said at least one of said plurality of marking areas is located as a function of stored predetermined distances measured with respect to said dimensions of said type of transaction document identified, said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory; and

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means.

5. An apparatus according to claim 4, wherein said identifying means comprises:

means for finding a leading edge of said transaction document by probing said columns of said image memory as said rows of bit signals are stored; and

means for finding side edges of said transaction document by probing said rows of said image memory such that, once side edges are found, the width of said document is realized.

6. An apparatus according to claim 5, wherein one of said side edges is found by calibration of said image memory, said one of said side edges corresponding to a side edge of said transaction document being forced against an alignment rail as said document is transported across said sensor means.

7. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel areas;

transform means for receiving said output signals and generating bit signals representative of each pixel area;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating comprising,

means for identifying a type of transaction document by probing a predetermined plurality of rows of said image memory means to determine dimensions of said document, said type of document having predetermined dimensions;

means for probing at least one column of said image memory means to locate a first mark position, the image data of said document including a plurality of mark positions; and

means for locating the at least one portion of image memory means representative of said at least one of said plurality of marking areas as a function of a predetermined distance from said first mark position to said at least one marking area dependent upon said type of transaction document identified,

said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory; and

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means.

8. An apparatus according to claim 7, further comprising means for controlling the speed at which said document is transported across said sensor means as a function of said plurality of mark positions of said document.

9. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel areas;

transform means for receiving said output signals and generating bit signals representative of each pixel area;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory; and

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means, said identifying means comprising,

means for probing a plurality of lines of bit signals representative of pixel areas extending across said marking area within said at least one portion of said image memory means in order to identify whether said lines contain at least one bit signal representative of a dark pixel area;

means for comparing the number of lines containing said at least one bit signal to at least one predetermined number of lines; and

means for filtering the result of said means for comparing in order to identify whether a mark appears in said at least one marking area.

10. An apparatus according to claim 9 wherein said means for filtering comprises means for carrying out the following process:

if said means for probing identifies a number of lines less than a first predetermined number of lines but more than a second predetermined number of lines, counting the number of bit signals representative of dark pixel areas in said portion of image memory means representative of said at least one marking area and concluding that there is a mark in said at least one marking area if said number of bit signals counted is greater than a predetermined number of bit signals, otherwise concluding that no mark is present in said marking area;

if said means for probing identifies a number of lines greater than said first predetermined number of lines, concluding that there is a mark in said at least one marking area; and

if said means for probing identifies a number of lines less than said second predetermined number of lines, concluding that there is no mark in said marking area.

11. An apparatus according to claim 9 wherein said means for filtering comprises means for carrying out the following process:

if said means for probing identifies a number of lines less than a first predetermined number of lines but more than a second predetermined number of lines, applying a neural network means to said portion of said image memory means representative of said at least one marking area, said neural network means for determining if a mark is placed in said marking area;

if said means for probing identifies a number of lines greater than said first predetermined number of lines, concluding that there is a mark in said at least one marking area; and

if said means for probing identifies a number of lines less than said second predetermined number of lines, concluding that there is no mark in said marking area.

12. An apparatus according to claim 9 wherein said means for filtering comprises:

means for counting said bit signals representative of dark pixel areas in said at least one marking area whenever said means for probing identifies all said plurality of lines as having at least one bit signal representative of a dark pixel area; and

means for identifying that a mark previously placed in the marking area has been scratched out by comparing said number of bit signals to a certain percentage of overall bit signals representative of said at least one marking area.

13. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel areas;

transform means for receiving said output signals and generating bit signals representative of each pixel area;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory;

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means; and

means for compensating for distortion across a row of pixel areas when the row is sensed by said sensor means so that probing of rows of bit signals of said image memory representative of said at least one marking area is accurately performed when said marking area is located and marks therein are identified.

14. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel areas;

transform means for receiving said output signals and generating bit signals representative of each pixel area;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory;

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means; and

means for compensating for distortion across a column of pixel areas when a plurality of rows are sensed so that probing of columns of said bit signals of said image memory representative of said at least one marking area is accurately performed when said marking area is located and marks therein are identified.

15. An apparatus for reading image data on a transaction document, said image data including a plurality of marking areas employed by a user to record marks, the apparatus comprising:

sensor means for sensing, one row at a time, a plurality of rows of image data as said document is transported across said sensor means, each row including a plurality of columns, said sensor means comprising means for generating output signals representative of said pixel area;

transform means for receiving said output signals and generating bit signals representative of each pixel area;

image memory means for storing said bit signals, said image memory means being organized into rows and columns of bit signals corresponding to said plurality of rows and columns of said pixel areas of said image data;

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating being operative after rows of bit signals representative of said at least one marking area are stored in said image memory means and while additional rows of bit signals representative of other image data are being sensed, transformed, and stored in said image memory;

means for identifying marks made in said at least one marking area while said additional rows of bit signals are being stored and while other marking areas are being located by probing said bit signals within said image memory means; and

means for compensating for an improper angle of said document as it is transported across said sensor means so that probing of said rows and columns of said bit signals of said image memory representative of said at least one marking area is accurately performed when said marking area is located and marks therein are identified.

16. An apparatus for reading information on a transaction document having image data thereon, said image data including at least one marking area for a user to place a transaction mark, comprising:

means for generating bit signals representative of rows and columns of dark or light pixel areas of said image data;

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data of said document;

means for locating at least one portion of said image memory representative of said at least one marking area as a function of particular reference characteristics of said document, said locating means comprising,

means for identifying a type of transaction document by probing a predetermined plurality of rows of said image memory to determine dimensions of said document, said type of document having predetermined dimensions, and

means for locating the at least one portion of image memory representative of said at least one of said plurality of marking areas as a function of stored predetermined distances measured with respect to said dimensions of said type of transaction document identified; and

means for identifying whether said at least one marking area contains a mark or lacks a mark by probing a plurality of lines of said bit signals of said image memory representative of pixel areas extending across said marking areas.

17. An apparatus for reading information on a transaction document having image data thereon, said image data including at least one marking area for a user to place a transaction mark, comprising:

means for generating bit signals representative of rows and columns of dark or light pixel areas of said image data;

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data of said document;

means for locating at least one portion of said image memory representative of said at least one marking area as a function of particular reference characteristics of said document by probing said bit signals of said image memory representative of a plurality of predetermined columns of said document and by locating at least one strobe mark, said marking area being a predetermined distance from said at least one strobe mark; and

means for identifying whether said at least one marking area contains a mark or lacks a mark by probing a plurality of lines of said bit signals of said image memory representative of pixel areas extending across said marking areas.

18. An apparatus for reading information on a transaction document having image data thereon, said image data including at least one marking area for a user to place a transaction mark, comprising:

means for generating bit signals representative of rows and columns of dark or light pixel areas of said image data;

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data of said document;

means for locating at least one portion of said image memory representative of said at least one marking area as a function of particular reference characteristics of said document; and

means for identifying whether said at least one marking area contains a mark or lacks a mark by probing a plurality of lines of said bit signals of said image memory representative of pixel areas extending across said marking areas, said identifying means comprising,

means for probing said plurality of lines of bit signals of said image memory representative of said pixel areas within said at least one marking area to identify whether said lines contain at least one bit signal representative of a dark pixel area;

means for comparing the number of lines containing said at least one bit signal to at least one predetermined number of lines; and

means for filtering the result of said means for comparing to identify whether a mark appears in said at least one marking area.

19. An apparatus according to claim 18 wherein said means for filtering comprises means for carrying out the following process:

if said means for probing identifies a number of lines less than a first predetermined number of lines but more than a second predetermined number of lines, counting the number of bit signals representative of dark pixel areas in said portion of image memory representative of said at least one marking area and concluding that there is a mark in said at least one marking area if said number of bit signals counted is greater than a predetermined number of bit signals, otherwise concluding that no mark is present in said marking area;

if said means for probing identifies a number of lines greater than said first predetermined number of lines, concluding that there is a mark in said at least one marking area; and

if said means for probing identifies a number of lines less than said second predetermined number of lines, concluding that there is no mark in said marking area.

20. An apparatus according to claim 18 wherein said means for filtering comprises means for carrying out the following process:

if said means for probing identifies a number of lines less than a first predetermined number of lines but more than a second predetermined number of lines, applying a neural network means to said portion of said image memory representative of said at least one marking area, said neural network comprising means for determining if a mark is placed in said marking area;

if said means for probing identifies a number of lines greater than said first predetermined number of lines, concluding that there is a mark in said at least one marking area; and

if said means for probing identifies a number of lines less than said second predetermined number of lines, concluding that there is no mark in said marking area.

21. An apparatus according to claim 18 wherein said means for filtering comprises:

means for counting said bit signals representative of dark pixel areas in said at least one marking area whenever said means for probing identifies all said plurality of lines as having at least one bit signal representative of a dark pixel area; and

means for identifying that a mark previously placed in the marking area has been scratched out by comparing said number of bit signals representative of dark pixel areas to a certain percentage of overall bit signals representative of said at least one marking area.

22. An apparatus for reading information on a transaction document having image data thereon, said image data including a plurality of marking areas employed by a user to record marks, said apparatus comprising:

sensor means for sensing at least a portion of said document;

means responsive to said sensor means for generating bit signals representative of pixel areas of said image data;

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data on said transaction document;

means for identifying marks made on a preselected portion of said transaction document stored in image memory while bit signals are being generated for additional portions of said transaction document that are being sensed, whereby marks are identified by determining the status of a portion of said bit signals in said image memory representative of said preselected portion; and

means for locating at least one portion of said image memory means representative of at least one of said plurality of marking areas of said transaction document, said means for locating comprising,

means for identifying a type of transaction document by probing a predetermined plurality of rows of said image memory means in order to determine dimensions of said document; and

means for locating said at least one portion of image memory means representative of said at least one of said plurality of marking areas as a function of stored predetermined distances measured with respect to said dimensions of said type of transaction document identified.

23. An apparatus for reading information on a transaction document having image data thereon, said apparatus comprising:

sensor means for sensing at least a portion of said document;

means responsive to said sensor means for generating bit signals representative of pixel areas of said image data;

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data on said transaction document;

means for identifying marks made on a preselected portion of said transaction document stored in image memory while bit signals are being generated for additional portions of said transaction document that are being sensed, whereby marks are identified by determining the status of a portion of said bit signals in said image memory representative of said preselected portion; and

means for compensating for distortion across a row of pixels when the row is sensed by said sensor means so that determining the status of said digital bits representative of said particular document portion is accurate.

24. An apparatus for reading information on a transaction document having image data thereon, said apparatus comprising:

sensor means for sensing at least a portion of said document;

means responsive to said sensor means for generating bit signals representative of pixel areas of said image data;

.

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data on said transaction document;

means for identifying marks made on a preselected portion of said transaction document stored in image memory while bit signals are being generated for additional portions of said transaction document that are being sensed, whereby marks are identified by determining the status of a portion of said bit signals in said image memory representative of said preselected portion; and

means for compensating for distortion across a column of pixels when the column is sensed by said sensor means so that determining the status of said digital bits representative of said preselected portion of said document is accurate.

25. An apparatus for reading information on a transaction document having image data thereon, said apparatus comprising:

sensor means for sensing at least a portion of said document;

means responsive to said sensor means for generating bit signals representative of pixel areas of said image data;

an image memory for storing said bit signals, said image memory being organized in rows and columns corresponding to said pixel areas of said image data on said transaction document;

means for identifying marks made on a preselected portion of said transaction document stored in image memory while bit signals are being generated for additional portions of said transaction document that are being sensed, whereby marks are identified by determining the status of a portion of said bit signals in said image memory representative of said preselected portion; and

means for compensation for an improper angle of said document as at least one of said document and said sensor means are moved relative to each other so that said determining the status of said digital bits that are representative of said particular document portion is accurately performed.