Photographic document imaging system

• US 20060045379A1
• Filed: 08/26/2004
• Published: 03/02/2006
• 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 7,593,595 B2
• Time in Patent Office: Days
• US Class Current: 382/276
• 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, said captured image comprising an imaged document, said method comprising:

detecting graphical information in said captured image related to edges of said imaged document;

isolating said imaged document from background of said captured image based on graphical information related to edges of said imaged document;

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

resampling pixels of said imaged document based on said computed deviations;

detecting graphical information in said captured image related to the orientation of said imaged document;

rotating said imaged document based on graphical information related to the orientation of said imaged document.

2. A method for processing a captured image that comprises an imaged document;

said method comprising;

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

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

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

3. A method for processing a captured image that comprises an imaged document;

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

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

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

computing deviation between coordinates of said corners of imaged document and coordinates of corners of a non-distorted perspective of said imaged document;

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.

4. The method recited in claim 3, further comprising 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 direction of said lines of text of said non-distorted imaged document with respect to dimensions of said edges of imaged document;

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

5. The method recited in claim 3, further comprising 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 direction of said lines of text of said non-distorted imaged document with respect to dimensions of said edges of imaged document;

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

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

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

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

7. A system for processing a captured image, said captured image comprising an imaged document, said system comprising:

means for detecting the edges of said imaged document;

means for reducing distortions of said imaged document;

means for rotating said captured image to proper orientation.

8. An apparatus for capturing an image comprised of a document, comprising:

a base wherein said document is placed;

a stand extending vertically from said base wherein said stand houses a digital camera positioned to capture said image;

a system for storing and processing said image coupled to said digital camera.

9. An apparatus as recited in claim 8, further comprising:

a computer readable medium for processing said image, the computer readable 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 said captured image related to edges of said imaged document;

isolating said imaged document from background of said captured image based on graphical information related to edges of said imaged document;

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

resampling pixels of said imaged document based on said computed deviations;

detecting graphical information in said captured image related to the orientation of said imaged document;

rotating said imaged document based on graphical information related to the orientation of said imaged document.

10. A computer readable medium for processing said image, the computer readable 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 said captured image related to edges of said imaged document;

isolating said imaged document from background of said captured image based on graphical information related to edges of said imaged document;

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

resampling pixels of said imaged document based on said computed deviations;

detecting graphical information in said captured image related to the orientation of said imaged document;

rotating said imaged document based on graphical information related to the orientation of said imaged document.

11. 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 said captured image related to edges of said imaged document;

isolating said imaged document from background of said captured image based on graphical information related to edges of said imaged document;

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

resampling pixels of said imaged document based on said computed deviations;

detecting graphical information in said captured image related to the orientation of said imaged document;

rotating said imaged document based on graphical information related to the orientation of said imaged document.