Method of sensing coded data on a surface

• US 7,920,762 B2
• Filed: 01/20/2010
• Issued: 04/05/2011
• Est. Priority Date: 05/25/1999
• Status: Expired due to Fees

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul, Walmsley, Simon Robert
• Primary Examiner(s): Dang; Duy M
• Application Number:
  US12/690,864
• Publication Number:
  US 20100119159A1
• Time in Patent Office: 440 Days
• Field of Search: 382/202, 382/203, 382/275, 382312-315, 358/1.13, 358/1.15, 345/166, 345/179, 178/18.09
• US Class Current: 382/313
• CPC Class Codes: B41J 13/103 for the sheet feeding section
• CPC Class Codes: B41J 13/106 for the sheet output section
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/1752 Mounting within the printer
• CPC Class Codes: B41J 2/17523 Ink connection
• CPC Class Codes: B41J 2/17546 electronically
• CPC Class Codes: B41J 2/17553 Outer structure
• CPC Class Codes: B41J 2/17556 Means for regulating the pressure in the cartridge
• CPC Class Codes: B41J 2/17563 Ink filters
• CPC Class Codes: B41J 2/2114 Ejecting transparent or white coloured liquids, e.g. processing liquids B41J2/211 takes precedence
• CPC Class Codes: B42C 19/02 starting with single sheets
• CPC Class Codes: B42C 9/0006 by applying adhesive to a stack of sheets
• CPC Class Codes: B42C 9/0081 applying adhesive to individual sheets for binding them together by fusing, welding B42C9/0093
• CPC Class Codes: B65H 29/34 from supports slid from under the articles
• CPC Class Codes: B65H 37/04 for securing together articles or webs, e.g. by adhesive, stitching or stapling adhering replacement to expiring web during change of web roll B65H19/18
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0321 by optically sensing the absolute position with respect to a regularly patterned surface forming a passive digitiser, e.g. pen optically detecting position indicative tags printed on a paper sheet constructional details of pen-shaped pointing devices G06F3/03545, G06F3/03542, G06F3/037
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/142 : using hand-held instruments; Constructional details of the instruments
• CPC Class Codes: G06V 30/1423 : the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32
• CPC Class Codes: G06V 30/1426 : by sensing position defining codes on a support
• CPC Class Codes: G06V 30/1444 : Selective acquisition, locating or processing of specific regions, e.g. highlighted text, fiducial marks or predetermined fields
• CPC Class Codes: G06V 30/1448 : based on markings or identifiers characterising the document or the area
• CPC Class Codes: H04N 1/00127 : Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
• CPC Class Codes: H04N 1/00204 : with a digital computer or a digital computer system, e.g. an internet server programmed control between transmitter and receiver or between image input and image output device H04N1/32561
• CPC Class Codes: H04N 1/00244 : with a server, e.g. an internet server fax-servers or the like for store and forward H04N1/324
• CPC Class Codes: H04N 1/00326 : with a data reading, recognizing or recording apparatus, e.g. with a bar-code apparatus arrangements for the associated working of recording or reproducing apparatus with related apparatus G11B31/00
• CPC Class Codes: H04N 1/00358 : Type of the scanned marks
• CPC Class Codes: H04N 1/00376 : Means for identifying a mark sheet or area
• CPC Class Codes: H04N 1/00567 : Handling of original or reproduction media, e.g. cutting, separating, stacking
• CPC Class Codes: H04N 1/00968 : by scanning marks on a sheet mark-sheet input means H04N1/00355; sensing record carriers G06K7/00
• CPC Class Codes: H04N 1/32101 : Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
• CPC Class Codes: H04N 1/32122 : in a separate device, e.g. in a memory or on a display separate from image data
• CPC Class Codes: H04N 1/32128 : attached to the image data, e.g. file header, transmitted message header, information on the same page or in the same computer file as the image for information embedded in the image H04N1/32144
• CPC Class Codes: H04N 1/32771 : in response to a request, e.g. for a particular document
• CPC Class Codes: H04N 1/32778 : using a mark-sheet or machine-readable code request
• CPC Class Codes: H04N 2201/0082 : Image hardcopy reproducer H04N2201/0091 - H04N2201/0094 take precedence
• CPC Class Codes: H04N 2201/3243 : of type information, e.g. handwritten or text document
• CPC Class Codes: H04N 2201/3269 : of machine readable codes or marks, e.g. bar codes or glyphs
• CPC Class Codes: H04N 2201/327 : which are undetectable to the naked eye, e.g. embedded codes

Abstract

A method of sensing coded data on a surface is disclosed. Images of the coded data on the surface are captured using a sensor of a sensing device. The coded data is formed from tags, with each tag encoding a unique identity of a region of the surface and the position of the tag within the region. A perspective distortion of the coded data is estimated and compensated for when detecting data elements in the tags. The unique identity of the region from the images is determined, and the position of the sensing device within the region from the position of at least one tag in at least one image captured by the sensor is determined.

Claims

1. A method of sensing coded data on a surface, the method comprising the steps of:

capturing images of the coded data on the surface using a sensor of a sensing device, the coded data comprising a plurality of tags, each tag encoding a unique identity of a region of the surface and the position of the tag within the region;

estimating a perspective distortion of the coded data;

compensating for the perspective distortion when detecting data elements in the tags;

determining the unique identity of the region from the images;

determining the position of the sensing device within the region from the position of at least one tag in at least one image captured by the sensor.

2. The method according to claim 1, comprising the further step of:

determining movement of the sensing device relative to the surface.

3. The method according to claim 2, comprising the further step of:

communicating the unique identity of the region, the at least one position of the sensing device within the region, and movement of the sensing device relative to the surface to a computer system.

4. The method according to claim 1, wherein each tag has four possible orientations relative to the surface and wherein each tag orientation contains one codeword placed at that orientation.

5. The method according to claim 2, wherein the coded data further includes periodic elements, the movement being determined using at least one of the periodic elements.

6. The method according to claim 5, comprising the further step of:

estimating a distance of the sensing device from one of the determined position or periodic element.

7. The method according to claim 1, comprising the further step of:

sensing an orientation of the sensing device relative to the coded data.

8. The method according to claim 1, wherein the movement includes acceleration of the sensing device relative to the region.

9. The method according to claim 8, wherein the acceleration includes at least two substantially orthogonal components of acceleration.