SYSTEM FOR IDENTIFYING PHYSICAL PAGE CONTAINING PRINTED TEXT

• US 20110292463A1
• Filed: 03/18/2011
• Published: 12/01/2011
• Est. Priority Date: 05/31/2010
• Status: Abandoned Application

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Napper, Jonathon Leigh, Lapstun, Paul
• Application Number:
  US13/050,942
• Publication Number:
  US 20110292463A1
• Time in Patent Office: Days
• US Class Current: 358/462
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 2356/00 Detection of the display position w.r.t. other display screens
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion telephones including GPS signal receivers H04M2250/10
• CPC Class Codes: H04M 2250/52 including functional features of a camera constructional features concerning the integration of cameras in portable phones H04M1/0264
• CPC Class Codes: H04N 1/00129 with a display device, e.g. CRT or LCD monitor with a television apparatus H04N1/00283; arrangements for control of display devices G09G

Abstract

A system for identifying a physical page containing printed text from a plurality of page fragment images. The system includes: (A) a handheld electronic device having: a camera for capturing a plurality of page fragment images at a plurality of different capture points when the device is moved across the physical page; motion sensing circuitry for measuring a displacement or a direction of movement; and a transceiver; (B) a processing system configured for: performing OCR on each captured page fragment image to identify a plurality of glyphs in a two-dimensional array; and creating a glyph group key for each page fragment image; and (C) an inverted index of the glyph group keys.

Claims

1. A system for identifying a physical page containing printed text from a plurality of page fragment images, said system comprising:

(A) a handheld electronic device configured for placement in contact with a surface of the physical page, said device comprising;

a camera for capturing a plurality of page fragment images at a plurality of different capture points when said device is moved across said physical page;

motion sensing circuitry for measuring a displacement or a direction of movement; and

a transceiver;

(B) a processing system configured for;

performing OCR on each captured page fragment image to identify a plurality of glyphs in a two-dimensional array; and

creating a glyph group key for each page fragment image, said glyph group key containing n×

m glyphs, where n and m are integers from 2 to 20; and

(C) an inverted index of said glyph group keys,

wherein said processing system is further configured for;

looking up each created glyph group key in an inverted index of glyph group keys;

comparing the displacement or direction between glyph group keys in said inverted index with a measured displacement or direction between the capture points for corresponding glyph group keys created using said OCR; and

identifying a page identity corresponding to said physical page using said comparison.

2. The system of claim 1, wherein said processing system is comprised of:

a first processor contained in said handheld electronic device and a second processor contained in a remote computer system.

3. The system of claim 2, wherein said inverted index is stored in said remote computer system.

4. The system of claim 1, wherein, in use, a plane of the handheld electronic device is parallel with a surface of the page, such that a pose of the camera is fixed and normal relative to the surface.

5. The system of claim 1, wherein each captured page fragment image has substantially consistent scale and illumination with no perspective distortion.

6. The system of claim 1, wherein a field of view of the camera has an area of less than about 100 square millimeters.

7. The system of claim 1, wherein the camera has an object distance of less than 10 mm.

8. The system of claim 1, wherein said processing system is further configured for:

retrieving a page description corresponding to said page.

9. The system of claim 8, wherein said processing system is further configured for:

comparing a fine alignment of imaged glyphs with a fine alignment of glyphs described by said retrieved page description; and

identifying a position of said device relative to said physical page.

10. The method of claim 1, wherein said processing system is further configured for:

employing a scale-invariant feature transform (SIFT) technique to augment said page identification.

11. The system of claim 1, wherein said motion sensing circuitry utilizes at least one of:

an optical mouse technique;

detecting motion blur;

one or more accelerometer signals; and

decoding a coordinate grid pattern.

12. The system of claim 1, wherein said motion sensing circuitry is comprised of said camera and said processing system.

13. The system of claim 1, wherein said inverted index comprises glyph group keys for skewed arrays of glyphs.

14. The system of claim 1, wherein said processing system is further configured for utilizing contextual information to identify a set of candidate pages.

15. The method of claim 11, wherein said contextual information comprises at least one of:

an immediate page or publication with which a user has been interacting;

a recent page or publication with which a user has been interacting;

publications associated with a user;

recently published publications;

publication printed in a user'"'"'s preferred language;

publications associated with a geographic location of a user.