PHOTOGRAPHIC DOCUMENT IMAGING SYSTEM

• US 20090238485A1
• Filed: 06/05/2009
• Published: 09/24/2009
• Est. Priority Date: 08/26/2004
• Status: Active Grant

• Current Assignee: Compulink Management Center Incorporated
• Original Assignee: Compulink Management Center Incorporated
• Inventors: Clegg, Zachariah, Darpinian, James, Rapelje, Kurt A., Dodds, Zachary B., Adams, William J., Andree, Zachary, Heaney, Edward P. JR.
• Granted Patent: US 7,835,589 B2
• Time in Patent Office: Days
• US Class Current: 382/256
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/1448 based on markings or identifiers characterising the document or the area
• CPC Class Codes: G06V 30/412 Layout analysis of documents structured with printed lines or input boxes, e.g. business forms or tables
• CPC Class Codes: H04N 1/3878 Skew detection or correction

Abstract

An apparatus and method for processing a captured image and, more particularly, for processing a captured image comprising a document. In one embodiment, an apparatus comprising a camera to capture documents is described. In another embodiment, a method for processing a captured image that includes a document comprises the steps of distinguishing an imaged document from its background, adjusting the captured image to reduce distortions created from use of a camera and properly orienting the document is described.

Claims

1. A method for processing a captured image that comprises an imaged document with perspective distortion;

said method comprising;

detecting graphical information in the captured image relating to the transition between said imaged document and the remainder of said captured image;

selecting one or more lines from said graphical information corresponding to edges of said imaged document;

calculating corners of said imaged document based on intersections of said one or more lines corresponding to edges of said imaged document;

isolating said imaged document from background of said captured image based on said one or more lines corresponding to edges of said imaged document;

computing deviations of said imaged document from a non-distorted perspective of said imaged document; and

generating a new image of said imaged document with reduced perspective distortion based on said computed deviations.

2. A method recited in claim 1, wherein the step of generating a new image of said imaged document with reduced perspective distortion based on said computed deviations comprises the process of:

mapping coordinates of pixels of said imaged document to coordinates corresponding to a non-distorted perspective of said imaged document based on said computed deviation.

3. A method recited in claim 1, further comprises the steps of:

converting said non-distorted imaged document into a two-color representation of said imaged document;

calculating pixel intensity of said two-color representation along the vertical axis of said non-distorted imaged document;

calculating pixel intensity of said two-color representation along the horizontal axis of said non-distorted imaged document;

identifying contrasts in pixel intensities along vertical and horizontal axes of said non-distorted imaged document;

identifying lines of text of said imaged document based on said contrasts in pixel intensities;

determining format of said non-distorted imaged document based on the direction of said lines of text of said non-distorted imaged document with respect to dimensions of said edges of said imaged document;

rotating said non-distorted imaged document according to said determination of format of said non-distorted imaged document.

4. The method recited in claim 3, further comprising the steps of:

dividing said lines of text into three portions along the longitudinal axis of said lines of text;

determining orientation of said lines of text based on a comparison of pixel intensities of said portions of said lines of text;

rotating said non-distorted imaged document based on said determination of orientation.

5. A computer readable storage medium for processing a captured image, said captured image comprising an imaged document, the computer readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause the one or more processors to perform the computer-implemented steps of:

detecting graphical information in the captured image relating to the transition between said imaged document and the remainder of said captured image;

selecting one or more lines from said graphical information corresponding to edges of said imaged document;

calculating corners of said imaged document based on intersections of said one or more lines corresponding to edges of said imaged document;

isolating said imaged document from background of said captured image based on said one or more lines corresponding to edges of said imaged document;

computing deviations of said imaged document from a non-distorted perspective of said imaged document; and

generating a new image of said imaged document with reduced perspective distortion based on said computed deviations.

6. An apparatus for processing a captured image, said captured image comprising an imaged document, said apparatus comprising:

one or more processors; and

a memory communicatively coupled to the one or more processors, the memory including one or more sequences of one or more instructions which, when executed by the one or more processors, cause the one or more processors to perform the steps of;

detecting graphical information in the captured image relating to the transition between said imaged document and the remainder of said captured image;

selecting one or more lines from said graphical information corresponding to edges of said imaged document;

calculating corners of said imaged document based on intersections of said one or more lines corresponding to edges of said imaged document;

isolating said imaged document from background of said captured image based on said one or more lines corresponding to edges of said imaged document;

computing deviations of said imaged document from a non-distorted perspective of said imaged document; and

generating a new image of said imaged document with reduced perspective distortion based on said computed deviations.