HYBRID SYSTEM FOR IDENTIFYING PRINTED PAGE

• US 20110293185A1
• 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, Gates, Robert Dugald
• Application Number:
  US13/050,935
• Publication Number:
  US 20110293185A1
• Time in Patent Office: Days
• US Class Current: 382/182
• 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 hybrid system for identifying a printed page. The system includes: (i) the printed page having human-readable content and a coding pattern printed in every interstitial space between portions of human-readable content, the coding pattern being either absent from the human-readable content or unreadable when superimposed with the human-readable content; and (ii) a handheld device for overlaying and contacting the printed page. The handheld device includes: a camera for capturing page fragment images; and a processor configured for: decoding the coding pattern and determining the page identity in the event that the coding pattern is visible in and decodable from the captured page fragment image; and otherwise initiating OCR or SIFT techniques to identify the page.

Claims

1. A hybrid system for identifying a printed page, said system comprising:

the printed page having human-readable content and a coding pattern printed in every interstitial space between portions of human-readable content, said coding pattern identifying a page identity, said coding pattern being either absent from said portions of human-readable content or unreadable when superimposed with said human-readable content;

a handheld device for overlaying and contacting said printed page, said device comprising;

a camera for capturing page fragment images; and

a processor configured for;

decoding the coding pattern and determining the page identity in the event that the coding pattern is visible in and decodable from the captured page fragment image; and

otherwise initiating at least one of OCR and SIFT techniques to identify said page from text and/or graphic features in said captured page fragment image.

2. The system of claim 1, wherein the coding pattern has less than 4% coverage on said page.

3. The system of claim 1, wherein the coding pattern is printed with yellow ink, said coding pattern being substantially invisible to a human eye by virtue of a relatively low luminance of yellow ink.

4. The system of claim 1, wherein said handheld device is a tablet-shaped device having a display screen on a first face and the camera positioned on an opposite second face, and wherein said second face is in contact with a surface of the printed page when said device overlays said page.

5. The system of claim 1, wherein a pose of the camera is fixed and normal relative to the surface when said device overlays said printed page.

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

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

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

9. The system of claim 1, wherein said device is configured for retrieving a page description corresponding to said page.

10. The system of claim 1, wherein said coding pattern identifies a plurality of coordinate locations on said page and said processor is configured for determining a position of said device relative to said page.

11. The system of claim 1, wherein said coding pattern is printed only in interstitial spaces between lines of text.

12. The system of claim 11, wherein said device further comprises means for sensing motion.

13. The system of claim 12, wherein said means for sensing motion utilizes at least one of:

an optical mouse technique;

detecting motion blur;

doubly integrating accelerometer signals; and

decoding a coordinate grid pattern.

14. The system of claim 12, wherein said device is configured for moving across said page, said camera is configured for capturing a plurality of page fragment images at a plurality of different capture points, and said processor is configured for initiating an OCR technique comprising the steps of:

measuring a displacement or direction of movement using said motion sensor;

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

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;

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 said page using said comparison.

15. The system of claim 14, wherein said OCR technique utilizes contextual information to identify a set of candidate pages.

16. The system of claim 15, wherein said contextual information comprises a page identity determined from the coding pattern of a page with which a user has immediately or recently interacted.

17. The system of claim 15, wherein said contextual information comprises at least one of:

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.

18. A printed page having human-readable lines of text and a coding pattern printed in every interstitial space between said lines of text, said coding pattern identifying a page identity and being printed with a yellow ink, said coding pattern being either absent from said lines of text or unreadable when superimposed with said text.

19. The printed page of claim 18, wherein said coding pattern identifies a plurality of coordinate locations on said page.

20. The printed page of claim 18, wherein said coding pattern is printed only in interstitial spaces between lines of text.