SYSTEM FOR MODIFYING CLASSIFICATION SCHEME FOR HANDWRITTEN CHARACTERS

• US 20100278429A1
• Filed: 07/12/2010
• Published: 11/04/2010
• Est. Priority Date: 10/15/2001
• Status: Active Grant

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Napper, Jonathon Leigh
• Granted Patent: US 7,903,879 B2
• Time in Patent Office: Days
• US Class Current: 382/186
• CPC Class Codes: G06V 30/244 using graphical properties, e.g. alphabet type or font

Abstract

A system for modifying a classification scheme for classifying hand-written characters. A memory stores the classification scheme, which includes a number of allographs, each allograph representing a respective style of a respective letter. A processor received data representing a hand-written character, and then selects an allograph representing the character. One or more of the allographs are then modified in accordance with the selection, to thereby reflect the fact that the allograph corresponds to a style of letter used by a user.

Claims

1. A system for modifying a classification scheme for classifying hand-written characters, said system comprising:

a memory storing the classification scheme so as to include a plurality of classes and user dependent weighted allographs, each class representing a respective letter and containing one or more of the allographs, each allograph including an associated weighting and representing a respective style of a respective letter and containing one or more prototypes, each prototype representing a variation in the respective allograph and being represented as a prototype vector, each prototype vector being formed from a number of values, each value quantifying a respective feature of the respective prototype vector; and

a processor configured for;

receiving data representing at least one handwritten character;

determining a selection value based on the similarity of the received character and a respective prototype vector of the stored classification scheme;

selecting a respective one of the prototype vectors of the stored classification scheme in accordance with the determined selection value;

selecting a class of the stored classification scheme in accordance with the selected prototype representing the character to thereby determine the letter represented by the character;

selecting one of the stored user dependent weighted allographs in accordance with the weightings and in accordance with said selected prototype vector representing the character;

modifying one or more of the allographs in the respective class in accordance with the selection by modifying the weighting of said one or more of the allographs; and

storing a modified classification scheme which includes said modified allographs.

2. The system according to claim 1, wherein the processor is configured for modifying the allographs to reflect that the selected allograph corresponds to a style of the respective letter used by the user.

3. The system according to claim 1, wherein the processor is configured for determining the selection value by a method comprising the steps of:

determining a feature vector representing the character, the feature vector being formed from a number of values, each value quantifying a respective feature of the character; and

determining a distance value representing the distance between the determined feature vector and the respective prototype vector.

4. The system according to claim 1, wherein the selection value is determined in accordance with the determined distance value and the weighting associated with the respective allograph.

5. The system according to claim 1, wherein the processor is configured for modifying the weighting of at least the allograph containing the selected prototype.

6. The system according to claim 1, wherein the processor is configured for selecting the prototype having the lowest selection value.

7. The system according to claim 1, wherein the processor is configured for modifying the weightings by at least one of:

decreasing the weighting for the allograph containing the selected prototype; and

,

increasing the weighting for one or more of the allographs that do not contain the selected prototype.

8. The system according to claim 6, wherein the processor is configured for increasing and/or decreasing the weighting of the allographs by a predetermined amount.

9. The system according to claim 1, wherein the processor is configured for:

selecting a reference prototype for each allograph to be modified;

determining the distance value for each reference prototype;

determining an average of the determined distance values; and

,

modifying the weighting of each allograph in accordance with the distance value of the respective reference prototype and the average distance value.

10. The system according to claim 9, wherein the processor is configured for selecting the reference prototype on the basis of being the prototype having the lowest distance value for the respective allograph.

11. The system according to claim 1, further comprising:

an optically imaging pen for generating the data representing the handwritten character.