Method and device for capturing a document

• US 10,255,496 B2
• Filed: 03/06/2017
• Issued: 04/09/2019
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: Ip Ot Sub Ulc
• Original Assignee: Open Text Sa Ulc (Open Text Corporation)
• Inventors: Copsey, Simon Dominic
• Primary Examiner(s): Mehta, Bhavesh M
• Assistant Examiner(s): Lemieux, Ian L
• Application Number:
  US15/450,889
• Publication Number:
  US 20170177932A1
• Time in Patent Office: 764 Days
• CPC Class Codes: G06V 10/17 using hand-held instruments
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image
• CPC Class Codes: G06V 10/247 by affine transforms, e.g. correction due to perspective effects; Quadrilaterals, e.g. trapezoids
• CPC Class Codes: G06V 30/142 using hand-held instruments; Constructional details of the instruments
• CPC Class Codes: G06V 30/40 Document-oriented image-based pattern recognition
• CPC Class Codes: G06V 40/67 by interactive indications to the user
• CPC Class Codes: H04N 1/3873 defined only by a limited number of coordinate points or parameters, e.g. corners, centre; for trimming

Abstract

A method and device for capturing a positionally corrected image of a document is disclosed. The method comprises the steps of: obtaining a two-dimensional image of the document with a mobile terminal apparatus; performing edge detection within the two-dimensional image to identify edges of the document; determining angles between detected edges; calculating, based on the detected edges and the angles determined, a three-dimensional position of the document relative to a position of the mobile terminal apparatus; calculating correction information to correct, by relative movement, the position of the document relative to the position of the mobile terminal apparatus; providing first guidance information derived from the correction information to a user of the mobile terminal apparatus, guiding the user to perform the relative movement; and capturing a positionally corrected image of the document. Thereby, the document can be captured with a quality sufficient to permit Optical Character Recognition (OCR).

Claims

1. A method, comprising:

performing, by a mobile device having at least one processor, a display, and a camera, edge detection within a two-dimensional image of a document to identify edges of the document, the two-dimensional image of the document obtained by the mobile device via the camera and displayed to a user of the mobile device via the display;

determining, by the mobile device, angles between detected edges of the document;

determining, by the mobile device based on the detected edges and the angles determined, a three-dimensional position of the document relative to a position of the mobile device;

determining, by the mobile device, correction information to correct, by relative movement, the three-dimensional position of the document relative to the position of the mobile device;

determining, by the mobile device, guidance information from the correction information; and

providing, by the mobile device, the guidance information to the user of the mobile device, the guidance information guiding the user to perform the relative movement such that when the three-dimensional position of the document is correct relative to the position of the mobile device, the mobile device automatically captures the document.

2. The method of claim 1, wherein the three-dimensional position of the document is correct relative to the position of the mobile device when an amount of relative movement is equal to or lower than a predetermined movement threshold.

3. The method of claim 1, wherein responsive to the user turning off an automatic document capture function via the display, the mobile device captures the document when instructed by the user.

4. The method of claim 1, wherein the guidance information is provided via the display, a sound device, a vibration device, or a combination thereof.

5. The method of claim 4, wherein the vibration device comprises vibration units and wherein the vibration units are controlled separately to guide the user to perform the relative movement.

6. The method of claim 1, wherein the display comprises an image quality indicator configured for indicating an amount of the relative movement performed by the user or an image quality value of the document.

7. The method of claim 1, wherein lines corresponding to the detected edges are displayed on the display to visualize the detected edges and guide the user.

8. An apparatus, comprising:

at least one processor;

a display;

a camera;

non-transitory computer memory; and

stored instructions translatable by the at least one processor to perform;

identifying edges of a document within a two-dimensional image of the document, the two-dimensional image of the document obtained by the apparatus via the camera and displayed to a user of the apparatus via the display;

determining angles between detected edges of the document;

determining, based on the detected edges and the angles determined, a three-dimensional position of the document relative to a position of the apparatus;

determining correction information to correct, by relative movement, the three-dimensional position of the document relative to the position of the apparatus;

determining guidance information from the correction information; and

providing the guidance information to the user of the apparatus, the guidance information guiding the user to perform the relative movement such that when the three-dimensional position of the document is correct relative to the position of the apparatus, the apparatus automatically captures the document.

9. The apparatus of claim 8, wherein the three-dimensional position of the document is correct relative to the position of the apparatus when an amount of relative movement is equal to or lower than a predetermined movement threshold.

10. The apparatus of claim 8, wherein responsive to the user turning off an automatic document capture function via the display, the apparatus captures the document when instructed by the user.

11. The apparatus of claim 8, wherein the guidance information is provided via the display, a sound device, a vibration device, or a combination thereof.

12. The apparatus of claim 11, wherein the vibration device comprises vibration units and wherein the vibration units are controlled separately to guide the user to perform the relative movement.

13. The apparatus of claim 8, wherein the display comprises an image quality indicator configured for indicating an amount of the relative movement performed by the user or an image quality value of the document.

14. The apparatus of claim 8, wherein lines corresponding to the detected edges are displayed on the display to visualize the detected edges and guide the user.

15. A computer program product comprising at least one non-transitory computer-readable storage medium including instructions translatable by at least one processor of an apparatus to perform:

identifying edges of a document within a two-dimensional image of the document, the two-dimensional image of the document obtained by the apparatus via a camera and displayed to a user of the apparatus via a display;

determining angles between detected edges of the document;

determining, based on the detected edges and the angles determined, a three-dimensional position of the document relative to a position of the apparatus;

determining correction information to correct, by relative movement, the three-dimensional position of the document relative to the position of the apparatus;

determining guidance information from the correction information; and

providing the guidance information to the user of the apparatus, the guidance information guiding the user to perform the relative movement such that when the three-dimensional position of the document is correct relative to the position of the apparatus, the apparatus automatically captures the document.

16. The computer program product of claim 15, wherein the three-dimensional position of the document is correct relative to the position of the apparatus when an amount of relative movement is equal to or lower than a predetermined movement threshold.

17. The computer program product of claim 15, wherein responsive to the user turning off an automatic document capture function via the display, the apparatus captures the document when instructed by the user.

18. The computer program product of claim 15, wherein the guidance information is provided via the display, a sound device, a vibration device, or a combination thereof.

19. The computer program product of claim 18, wherein the vibration device comprises vibration units and wherein the vibration units are controlled separately to guide the user to perform the relative movement.

20. The computer program product of claim 15, wherein the display comprises an image quality indicator configured for indicating an amount of the relative movement performed by the user or an image quality value of the document.