CA2022075A1 - Cross-product filter - Google Patents

Cross-product filter

Info

Publication number
CA2022075A1
CA2022075A1 CA2022075A CA2022075A CA2022075A1 CA 2022075 A1 CA2022075 A1 CA 2022075A1 CA 2022075 A CA2022075 A CA 2022075A CA 2022075 A CA2022075 A CA 2022075A CA 2022075 A1 CA2022075 A1 CA 2022075A1
Authority
CA
Canada
Prior art keywords
stroke
cross
product
product filter
vectors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA2022075A
Other languages
French (fr)
Other versions
CA2022075C (en
Inventor
James S. Lipscomb
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
James S. Lipscomb
International Business Machines Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by James S. Lipscomb, International Business Machines Corporation filed Critical James S. Lipscomb
Publication of CA2022075A1 publication Critical patent/CA2022075A1/en
Application granted granted Critical
Publication of CA2022075C publication Critical patent/CA2022075C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V30/00—Character recognition; Recognising digital ink; Document-oriented image-based pattern recognition
    • G06V30/10—Character recognition
    • G06V30/32—Digital ink
    • G06V30/333—Preprocessing; Feature extraction
    • G06V30/347—Sampling; Contour coding; Stroke extraction

Abstract

Method and apparatus for filtering a sequence of digital values representative of endpoints of vectors which represent the stroke of a writing instrument on a writing tablet. The cross-product and dot-product of the vectors comprising the stroke are computed to produce a sample of points which are close together where the stroke curves sharply, and which are farther apart where the stroke is substantially straight.
CA002022075A 1989-10-03 1990-07-26 Cross-product filter Expired - Fee Related CA2022075C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US416,564 1989-10-03
US07/416,564 US5023918A (en) 1989-10-03 1989-10-03 Cross-product filter

Publications (2)

Publication Number Publication Date
CA2022075A1 true CA2022075A1 (en) 1991-04-04
CA2022075C CA2022075C (en) 1996-01-02

Family

ID=23650454

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002022075A Expired - Fee Related CA2022075C (en) 1989-10-03 1990-07-26 Cross-product filter

Country Status (4)

Country Link
US (1) US5023918A (en)
EP (1) EP0421160A3 (en)
JP (1) JPH03125274A (en)
CA (1) CA2022075C (en)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5333209A (en) * 1992-03-24 1994-07-26 At&T Bell Laboratories Method of recognizing handwritten symbols
JP3192468B2 (en) * 1992-04-16 2001-07-30 パイオニア株式会社 Online handwritten character recognition device and recognition method
JP3155616B2 (en) * 1992-06-25 2001-04-16 キヤノン株式会社 Character recognition method and device
EP0578432A3 (en) * 1992-07-06 1994-06-22 Canon Kk Similarity determination among patterns using affine-invariant features
WO1994003853A1 (en) * 1992-07-29 1994-02-17 Communication Intelligence Corporation A method and apparatus for compression of electronic ink
EP0600585A3 (en) * 1992-11-20 1994-11-02 Mutoh Ind Ltd System for identifying freehand drawings.
JP3026698B2 (en) * 1993-05-27 2000-03-27 キヤノン株式会社 Image processing method and apparatus
JP2626528B2 (en) * 1993-11-22 1997-07-02 日本電気株式会社 Figure recognition device
DE69425412T2 (en) * 1993-11-23 2001-03-08 Ibm System and method for automatic handwriting recognition using a user-independent chirographic label alphabet
TW397951B (en) * 1995-06-05 2000-07-11 Motorola Inc Method and microprocessor for preprocessing handwriting having characters composed of a preponderance of straight line segments
JPH09223195A (en) * 1996-02-06 1997-08-26 Hewlett Packard Co <Hp> Character recognizing method
US5920647A (en) * 1997-08-12 1999-07-06 Motorola, Inc. Method and apparatus for recognition of hand-printed characters represented as an electronic ink stream using a box filtering technique
AU9115498A (en) * 1997-08-27 1999-03-16 Cybermarche, Inc. A method and apparatus for handwriting capture, storage, and ind exing
US7567711B2 (en) * 2005-08-01 2009-07-28 Microsoft Corporation Cleaning up of handwriting intra-stroke and inter-stroke overtracing
JP5879858B2 (en) * 2011-09-20 2016-03-08 富士ゼロックス株式会社 WRITING INFORMATION GENERATION DEVICE, WRITING INFORMATION GENERATION SYSTEM, AND PROGRAM

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993976A (en) * 1974-05-13 1976-11-23 The United States Of America As Represented By The Secretary Of The Air Force Method and apparatus for pattern analysis
US4282511A (en) * 1980-01-07 1981-08-04 Rca Corporation Apparatus for discerning the noticeable presence of spatial fluctuations of intensity within a two-dimensional visual field
US4534060A (en) * 1983-08-09 1985-08-06 Pencept, Inc. Method and apparatus for removing noise at the ends of a stroke
NO865239L (en) * 1985-04-26 1986-12-22 Battelle Memorial Institute PROCEDURE FOR COMPARISON OF A HANDWRITING WITH A REFERENCE WRITING.
US4731859A (en) * 1985-09-20 1988-03-15 Environmental Research Institute Of Michigan Multispectral/spatial pattern recognition system
US4837843A (en) * 1987-06-19 1989-06-06 Hughes Aircraft Company Hybrid optical and electronic associative memory

Also Published As

Publication number Publication date
US5023918A (en) 1991-06-11
CA2022075C (en) 1996-01-02
EP0421160A3 (en) 1992-11-04
JPH03125274A (en) 1991-05-28
EP0421160A2 (en) 1991-04-10

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Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed