IP Library Granted Patent US 7,791,756
Granted Patent B2
US 7,791,756 · App. 11/120,932 · Granted Sep 7, 2010

Methods for identifying marks using a digital master document and scanned image enhancement

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Quick Facts
Patent No.
US 7,791,756
App. No.
11/120,932
Granted
Sep 7, 2010
Kind
B2
Abstract

To reduce errors introduced by a scanner, an unmarked, digital master document may be generated and stored in digital form so that subsequent scanning of the document is unnecessary to place it in digital form for comparison to a marked version of the document. Additionally, regions or fields, rather than the entire digital master document, may be individually created, stored, and subsequently used for comparison to corresponding portions of a marked version. Further, test targets or patterns may be inserted into the content of a digital master document. Characteristics of image quality degeneration and distortion can be extracted from printed versions of the test targets or patterns and used to effect closed loop control to digitally reduce image quality degeneration caused by the scanner.

Claims (15)

1. A method for optical mark recognition, comprising:

generating a digital master document,

storing the digital master document,

printing a copy of the digital master document, wherein said printed copy receives at least one marking thereon;

scanning the printed copy after it receives the at least one marking thereon;

comparing the digital master document to the scanned copy to identify the at least one marking,

wherein generating the digital master document comprises generating the digital master document based on a user defined selection of at least one stored field from a plurality of stored fields; and

storing field characteristic information corresponding to the at least one selected stored field prior to the comparing the digital master document to the scanned copy and prior to the scanning of the printed copy.

2. The method of claim 1 , further comprising creating the at least one stored field prior to the generating the digital master document.

3. The method of claim 2 , wherein the creating the at least one stored field comprises generating the at least one stored field using a page description language.

4. The method of claim 1 , further comprising digitizing the at least one stored field.

5. The method of claim 1 , wherein the field characteristic information identifies a location of the at least one selected stored field in the digital master document.

6. The method of claim 1 , wherein the comparing the digital master document to the scanned copy further comprises comparing the digital master document to the scanned copy using the at least one selected stored field and the field characteristic information.

7. The method of claim 5 , further comprising automatically identifying a location of one or more fields within the scanned copy, wherein the location of the one or more fields within the scanned copy corresponds to the location of the at least one selected stored field in the digital master document.

8. The method of claim 7 , wherein automatically identifying the location of one or more fields within the scanned copy further comprises automatically identifying the location of the one or more fields within the scanned copy using the field characteristic information.

Assignments (8)
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0192 →
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0293 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: CITIBANK, N.A.
Reel/Frame 073007/0118 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: JEFFERIES FINANCE LLC
Reel/Frame 073007/0346 →
RELEASE OF SECURITY INTEREST Recorded Jan 18, 2024
From: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 066345/0026 →
CORRECTIVE ASSIGNMENT TO CORRECT THE INCORRECT U.S. PATENT NUMBER PREVIOUSLY RECORDED AT REEL: 046989 FRAME: 0396. ASSIGNOR(S) HEREBY CONFIRMS THE PATENT SECURITY AGREEMENT. Recorded Oct 24, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 047760/0795 →
PATENT SECURITY AGREEMENT Recorded Aug 30, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 046989/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 3, 2005
From: CUI, CHENGWU
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 016541/0258 →