Method and apparatus for classifying an input character

• US 7,697,761 B2
• Filed: 02/14/2008
• Issued: 04/13/2010
• Est. Priority Date: 10/15/2001
• Status: Expired due to Fees

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Napper, Jonathon Leigh
• Primary Examiner(s): Ahmed; Samir A.
• Assistant Examiner(s): RASHIDIAN, MOHAMMAD M
• Application Number:
  US12/031,615
• Publication Number:
  US 20080144938A1
• Time in Patent Office: 789 Days
• Field of Search: 382/159, 382/164, 382/171, 382/173, 382/177, 382/179, 382/181, 382185-187, 382/216, 382226-228, 382/259, 382/300, 382202-203, 382/209, 382/213, 382/224
• US Class Current: 382/186
• 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 30/244 using graphical properties, e.g. alphabet type or font

Abstract

A method for classifying an input character, the method comprising the steps of, in a processing system, for a plurality of character models, decomposing the input character into one or more segments in accordance with a segmentation scheme associated with the character model, and evaluating the one or more segments against a segment model associated with the character model, by using fuzzy logic rules to produce a score indicative of the conformity with the segment model, the method further including selecting the character model that produced the highest score, and classifying the input character as a character associated with the character model that produced the highest score.

Claims

1. A method for classifying an input character, the method comprising the steps of, in a processing system, using a processor to implement:

(a) for each of a plurality of character models, each character model being associated with a possible output character, and defines a model specific segmentation scheme for that possible output character and an associated segment model;

(i) decomposing the input character into one or more segments in accordance with the model specific segmentation scheme of the respective character model; and

(ii) evaluating the one or more segments against the segment model of the respective character model, by using fuzzy logic rules, to produce a score indicative of the conformity of the one or more segments with the segment model;

(b) selecting the character model that produced the highest score; and

,

(c) classifying the input character as the output character associated with the character model that produces the highest score, wherein the step of decomposing the input character into one or more segments is performed such that each segment has a minimum length corresponding to the number of points in the stroke of the character and a minimum length threshold.

2. The method of claim 1, wherein each character model has a plurality of associated segmentation schemes.

3. The method of claim 2, wherein the method includes, determining whether the input character can be segmented with the segmentation scheme, and if the input character cannot be segmented, changing the segmentation scheme.

4. The method of claim 1, wherein the method includes classifying the input character as any one of a letter, a number, or a punctuation mark.

5. The method of claim 1, wherein the score rewards closer conformance to an ideal.

6. The method of claim 1, wherein the method includes defining different rules for decomposing the input character into one or more segments for different character models.

7. An apparatus for classifying an input character, the apparatus including a processing system, the processing system being configured to:

(a) for each of a plurality of character models, each character model being associated with a possible output character, and defines a model specific segmentation scheme for that possible output character and an associated segment model;

(i) decompose the input character into one or more segments in accordance with the model specific segmentation scheme of the respective character model; and

(ii) evaluate the one or more segments against the segment model of the respective character model, by using fuzzy logic rules to produce a score indicative of the conformity of the one or more segments with the segment model;

(b) select the character model that produced the highest score; and

,

(c) classify the input character as the output character associated with the character model that produced the highest score, wherein decomposing the input character into one or more segments is performed such that each segment has a minimum length corresponding to the number of points in the stroke of the character and a minimum length threshold.

8. The apparatus of claim 7, wherein the apparatus includes an input surface responsive to movement of a stylus thereupon for producing an input stimulus, the processing system being configured to receive the input stimulus as the input character.