System and methods for providing robust keyword selection in a personal digital notepad

• US 6,333,995 B1
• Filed: 01/29/1999
• Issued: 12/25/2001
• Est. Priority Date: 01/29/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Perrone, Michael P.
• Primary Examiner(s): Bella, Matthew C.
• Assistant Examiner(s): DESIRE, GREGORY M
• Application Number:
  US09/240,147
• Time in Patent Office: 1,061 Days
• Field of Search: 382/186-189, 382/177-180, 382/203, 382/311, 382/224-225, 382/270, 382/272, 707/530
• US Class Current: 382/187
• CPC Class Codes: G06V 30/10 Character recognition
• 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 30/1444 Selective acquisition, locating or processing of specific regions, e.g. highlighted text, fiducial marks or predetermined fields

Abstract

Keyword selection methods for use with handwriting recording devices such as a personal digital notepad (PDN) which provide robust keyword selection by making stroke membership and selection more flexible and, therefore, less prone user error/variability. In one aspect of the present invention, a method for selecting a keyword in a handwriting recording device comprises the steps of invoking a keyword selection mode writing bounding strokes around handwritten strokes selected by a user for designation as a keyword; defining a bounding region as the area contained within the bounding strokes; and determining keyword membership of a recorded stroke based on a relation between the recorded stroke and the defined bounding region. Keyword membership may be determined by including only those recorded strokes which fall entirely within the bounding region. In another aspect, keyword membership is determined by including only those strokes for which the ratio of the length of the stroke inside the bounding region to the total length of the stroke is larger than some predetermined or user-specified threshold. In another aspect, keyword membership can be implemented to include only those recorded strokes having a beginning, an end, or a beginning and end included within the bounding region. In yet another aspect, the keyword membership is implemented by including or excluding as a keyword member a stroke having a cost factor which exceeds a prespecified threshold, wherein the cost factor is based on a distance from the bounding region of a portion of a stroke that is outside of the bounding region and the percentage of the stroke length which is outside the bounding region.

Claims

1. A method for selecting a keyword in a handwriting recording device having an electronic inking stylus and a digitizing tablet associated therewith, wherein the device records stroke data representing handwritten strokes concurrently produced on a writing medium placed over the digitizing tablet using the electronic inking stylus, the method comprising the steps of:

invoking a keyword selection mode, wherein the keyword selection mode allows a user to designate one or more recorded strokes as a reference keyword;

accepting as input, handwritten bounding strokes;

defining a bounding region as the area contained within the handwritten bounding strokes; and

determining keyword membership of a recorded stroke based on a relation between the recorded stroke and the defined bounding region,

wherein the step of determining keyword membership includes the steps of;

determining each stroke which is entirely contained and partially contained in the bounding region;

for each partially contained stroke, calculating a percentage of the stroke contained within the bounding region;

comparing each calculated percentage to a prespecified threshold; and

selecting as keyword members the strokes that are determined to be entirely contained within the bounding region and the partially contained strokes having a calculated percentage which exceeds the prespecified threshold.

2. The method of claim 1, wherein the step of determining keyword membership includes the steps of:

selecting as keyword members strokes that are fully contained within the bounding region; and

excluding as keyword members strokes that are partially contained within the bounding region.

3. The method of claim 1, wherein the prespecified threshold may be preselected by a user.

4. The method of claim 1, wherein the step of calculating a percentage of the stroke contained within the bounding region, includes the steps of:

calculating a length of the stroke and a length of the portion of the stroke contained within the bounding region; and

ratioing the length of the stoke portion within the bounding region to the length of the stroke.

5. The method of claim 1, wherein the step of determining keyword membership includes the steps of including strokes that are determined to have a beginning portion within the bounding region.

6. The method of claim 1, wherein the step of determining keyword membership includes the steps of including strokes that are determined to have an ending portion within the bounding region.

7. The method of claim 1, wherein the step of determining keyword membership includes the steps of including strokes that are determined to have a beginning portion and an ending portion within the bounding area.

8. The method of claim 1, wherein the step of invoking the keyword selection mode includes the steps of:

displaying a menu of keyword selection mode options; and

selecting a keyword selection mode from the displayed menu, wherein keyword membership determination is implemented in accordance with the selected mode.

9. A method for selecting a keyword in a handwriting recording device having an electronic inking stylus and a digitizing tablet associated therewith, wherein the device records stroke data representing handwritten strokes concurrently produced on a writing medium placed over the digitizing tablet using the electronic inking stylus, the method comprising the steps of:

invoking a keyword selection mode, wherein the keyword selection mode allows a user to designate one or more recorded strokes as a reference keyword;

accepting as input, handwritten bounding strokes;

defining a bounding region as the area contained within the handwritten bounding strokes; and

determining keyword membership of a recorded stroke based on a relation between the recorded stroke and the defined bounding region,

wherein the step of determining keyword membership includes the steps of;

determining each stroke which is entirely contained and partially contained in the bounding region;

for each partially contained stroke, calculating a cost factor based on distance from the bounding region of the portion of the partially contained stroke which is outside the bounding region and the percentage of the partially contained stroke which is outside the bounding region;

comparing each calculated cost factor to a prespecified threshold; and

selecting as keyword members the strokes that are determined to be entirely contained within the bounding region and the partially contained strokes having a calculated cost factor which exceeds the prespecified threshold.

10. The method of claim 9, wherein the cost factor for a partially contained stroke is defined as the average distance from the bounding region of the stroke portion outside the bounding region multiplied by the percentage of the stroke which is outside the bounding region.

11. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for selecting a keyword in a handwriting recording device, the method steps comprising:

invoking a keyword selection mode, wherein the keyword selection mode allows a user to designate one or more recorded strokes as a reference keyword;

accepting as input, handwritten bounding strokes;

defining a bounding region as the area contained within the handwritten bounding strokes; and

determining keyword membership of a recorded stroke based on a relation between the recorded stroke and the defined bounding region,

wherein the instructions for determining keyword membership include instructions for performing the steps of;

determining each stroke which is entirely contained and partially contained in the bounding region;

for each partially contained stroke, calculating a cost factor based on distance from the bounding region of the portion of the partially contained stroke which is outside the bounding region and the percentage of the partially contained stroke which is outside the bounding region;

comparing each calculated cost factor to a prespecified threshold; and

selecting as keyword members the strokes that are determined to be entirely contained within the bounding region and the partially contained strokes having a calculated cost factor which exceeds the prespecified threshold.

12. The program storage device of claim 11, wherein the instructions for determining keyword membership include instructions for performing the steps of:

selecting as keyword members strokes that are fully contained within the bounding region; and

excluding as keyword members strokes that are partially contained within the bounding region.

13. The program storage device of claim 11, wherein the instructions for determining keyword membership include instructions for including strokes that are determined to have a beginning portion within the bounding region.

14. The program storage device of claim 11, wherein the instructions for determining keyword membership include instructions for including strokes that are determined to have an ending portion within the bounding region.

15. The program storage device of claim 11, wherein the instructions for determining keyword membership include instructions for including strokes that are determined to have a beginning portion and an ending portion within the bounding area.

16. The program storage device of claim 11, wherein the cost factor for a partially contained stroke is defined as the average distance from the bounding region of the stroke portion outside the bounding region multiplied by the percentage of the stroke which is outside the bounding region.

17. The program storage device of claim 11, wherein the instructions for invoking the keyword selection mode include instructions for performing the steps of:

displaying a menu of keyword selection mode options; and

selecting a keyword selection mode from the displayed menu, wherein keyword membership determination is implemented in accordance with the selected mode.

18. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for selecting a keyword in a handwriting recording device, the method steps comprising:

invoking a keyword selection mode, wherein the keyword selection mode allows a user to designate one or more recorded strokes as a reference keyword;

accepting as input, handwritten bounding strokes;

defining a bounding region as the area contained within the handwritten bounding strokes; and

determining keyword membership of a recorded stroke based on a relation between the recorded stroke and the defined bounding region, wherein the instructions for determining keyword membership include instructions for performing the steps of;

determining each stroke which is entirely contained and partially contained in the bounding region;

for each partially contained stroke, calculating a percentage of the stroke contained within the bounding region,

comparing each calculated percentage to a prespecified threshold; and

selecting as keyword members the strokes that are determined to be entirely contained within the bounding region and the partially contained strokes having a calculated percentage which exceeds the prespecified threshold.

19. The program storage device of claim 18, wherein the prespecified threshold may be preselected by a user.

20. The program storage device of claim 18, wherein the instructions for calculating a percentage of the stroke contained within the bounding region include instructions for performing the steps of:

calculating a length of the stroke and a length of the portion of the stroke contained within the bounding region; and

ratioing the length of the stroke portion within the bounding region to the length of the stroke.