Handwriting recognition by character template

• US 5,303,312 A
• Filed: 09/08/1992
• Issued: 04/12/1994
• Est. Priority Date: 04/19/1991
• Status: Expired due to Fees

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Levy, Stephen E., Comerford, Liam D.
• Primary Examiner(s): COUSO, YON JUNG
• Application Number:
  US07/942,118
• Time in Patent Office: 581 Days
• Field of Search: 382/13, 382/12, 382/11, 382/29, 382/30, 340/706
• US Class Current: 382/189
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06V 10/17 using hand-held instruments

Abstract

A method for entry and recognition of elements from a set of symbols, involving a template of line segments displayed on an electronic writing surface. A stylus is applied to the electronic writing surface so as to trace a desired symbol. A computing arrangement is used to "snap" the strokes made by the stylus onto the corresponding template line segments. Upon completion of a symbol, a code is made to represent the line segments and this code is used to reference entries in a data structure to identify the appropriate corresponding computer code. If there is no match, the code for the line segments and a corresponding set of computer codes can be added to the table. This method takes advantage of natural handwriting skills and can be used for a variety of symbol sets.

Claims

1. A method of data entry using a graphic input and display tablet and a character recognition system including the steps of

displaying a template which defines strokes which can be recognized by said character recognition system,

inputting a locus on said graphic input and display tablet including a step of displaying said locus,

determining that entry of said locus is complete,

converting said locus to a glyph comprising one or more strokes of said template and displaying said strokes of said template corresponding to said locus while removing display of said locus,

determining that entry of said glyph is complete, and

generating a code corresponding to said one or more strokes in response to said step of determining said glyph is complete.

2. A method as recited in claim 1, including the further step of

touching up said strokes displayed by said step of displaying strokes corresponding to said locus.

3. A method as recited in claim 2, wherein said step of touching up said strokes displayed by said step of displaying strokes of said template corresponding to said locus comprises the further steps of

inputting a further locus on said graphic input and display tablet,

converting said further locus to one or more strokes of said template corresponding to said further locus,

comparing a stroke of said template corresponding to said further locus with each stroke of said template corresponding to said locus,

displaying or erasing from the display at least one stroke corresponding to said further locus in response to at least one result of said comparing step.

4. A method as recited in claim 1, wherein said step of displaying strokes of said template corresponding to said locus further includes

displaying a glyph corresponding to at least one segment of said template, said glyph having an appearance differing from but positionally related to said at least one stroke.

5. A method as recited in claim 4, wherein said step of displaying a glyph includes at least one of the steps of

displaying at least one of a looped riser and a looped descender, and

displaying a ligature.

6. A method as recited in claim 1, including the further steps of

determining when said step of generating a code finds no code corresponding to said one or more strokes and, responsive thereto,

prompting a user to designate a symbol corresponding to said strokes displayed by said step of displaying strokes corresponding to said locus and a code corresponding to said strokes displayed by said step of displaying strokes corresponding to said locus.

7. A method as recited in claim 1, wherein said graphic input and display tablet includes a plurality of said templates, said method including the further step of

determining movement of said locus between ones of said plurality of templates.

8. A method as recited in claim 7, including the further step of

synthesizing ligatures corresponding to said locus responsive to said step of determining movement of said locus between ones of said plurality of templates.

9. A method as recited in claim 7, wherein said step of converting said locus to one or more strokes is conducted in response to said step of determining movement of said locus between ones of said plurality of templates.

10. A method as recited in claim 9, including the further step of

synthesizing ligatures corresponding to said locus responsive to said step of determining movement of said locus between ones of said plurality of templates.

11. A data entry arrangement using a graphic input and display tablet and a character recognition system including

means for displaying a template which defines strokes which can be recognized by said character recognition system,

means for inputting a locus on said graphic input and display tablet including means for displaying said locus,

means for determining that entry of said locus is complete,

means for converting said locus to a glyph comprising one or more strokes of said template, including means for displaying said strokes of said template corresponding to said locus and removing display of said locus,

means for determining that entry of said glyph is complete, and

means for generating a code corresponding to said one or more strokes displayed and corresponding to said locus responsive to said means for determining that entry of said glyph is complete.

12. An arrangement as recited in claim 11, further including

a stylus and

means for touching up said strokes displayed by said means for displaying strokes corresponding to said locus.

13. An arrangement as recited in claim 12, wherein said means for touching up said strokes corresponding to said locus further includes

means for capturing a further locus on said graphic input and display tablet,

means for converting said further locus to one or more strokes of said template corresponding to said further locus,

means for comparing a stroke of said template corresponding to said further locus with each stroke of said template corresponding to said locus,

means for controlling said means for displaying said strokes corresponding to said locus to display or erase at least one stroke corresponding to said further locus in response to said means for comparing a stroke of said template corresponding to said further locus with each stroke of said template corresponding to said locus.

14. An arrangement as recited in claim 11, wherein said means for displaying strokes of said template corresponding to said locus further includes

means for displaying a glyph corresponding to at least one segment of said template, said glyph having an appearance differing from but positionally related to said at least one stroke.

15. An arrangement as recited in claim 14, wherein said means for displaying a glyph includes at least one of

means for displaying at least one of a looped riser and a looped descender, and

means for displaying a ligature.

16. An arrangement as recited in claim 11, further including

means for determining when said means for generating a code finds no code corresponding to said one or more strokes,

means for prompting a user to designate a symbol corresponding to said strokes displayed by said means for displaying strokes corresponding to said locus and a code corresponding to said strokes displayed by said means for displaying strokes corresponding to said locus, said means for prompting a user being responsive to said means for determining failure of said means for generating a code.

17. An arrangement as recited in claim 11, wherein said graphic input and display tablet includes a plurality of said templates, said arrangement further including

means for determining movement of said locus between ones of said plurality of templates.

18. A method as recited in claim 17, wherein said means for converting said locus to one or more strokes is responsive to said means for determining movement of said locus between ones of said plurality of templates.