Handwritten character recognition apparatus

• US 20020009226A1
• Filed: 04/19/2001
• Published: 01/24/2002
• Est. Priority Date: 04/20/2000
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ito, Yoshikatsu, Nakao, Ichiro
• Granted Patent: US 6,931,153 B2
• Time in Patent Office: Days
• US Class Current: 382/177
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32

Abstract

A handwritten character recognition apparatus has a character string input area of a size that allows a user to hand write a plurality of characters thereon using a stylus. A coordinate detection unit extracts a coordinate string for each stroke that forms the handwritten character string. An input completion judgement unit judges an immediately preceding handwritten character string to be complete if a time difference between a last coordinate of an immediately preceding stroke and a first coordinate of a stroke being input is at least a predetermined time, when the first coordinate of the stroke is detected in a first area of the character string input area. A character segmentation unit segments a stroke string for each character from all the strokes of the previously input hand written character string from which a character recognition unit recognizes each character and outputs a character string which is the recognition result.

Claims

1. A handwritten character recognition apparatus having a character string input area of a size that allows a plurality of characters to be handwritten thereon for a user to input a handwritten character string, comprising:

a coordinate string detection unit operable to detect a coordinate string of each stroke that makes up an input handwritten character string,

an input completion judgement unit operable to judge, when a first coordinate of one of the strokes is detected in a first area which is at a side of the character string input area where writing of the handwritten character string starts, whether an input of an immediately preceding handwritten character string is complete, and

a segmentation recognition unit operable to segment, when the input completion detection unit judges the input to be complete, stroke strings for each character from all the strokes of the immediately preceding handwritten character string, recognize each character, and output a character string which is a recognition result.

2. A handwritten character recognition apparatus according to claim 1, wherein the input completion judgement unit includes:

a first coordinate judgement unit operable to judge, when an X value of a first coordinate of a stroke is X1 or less, X1 being a width of the first area, that the first coordinate is in the first area.

3. A handwritten character recognition apparatus according to claim 2, wherein the input completion judgement unit further includes:

an X1 setting unit operable to receive a value of X1 according to a size of a handwritten character written by the user, the first coordinate judgement unit judging according to the received value of X1.

4. A handwritten character recognition apparatus according to claim 1, wherein the input completion judgement unit includes:

an input time measurement unit operable to measure a first input time which is an input time of a first coordinate of each stroke, and a second input time which is an input time of a last coordinate of each stroke, and

a time judgement unit operable to judge, when a time difference between the first input time of a stroke and a second input time of an immediately preceding stroke is at least a predetermined time, that the input of the immediately preceding handwritten character string is complete.

5. A handwritten character recognition apparatus according to claim 4, wherein the input completion judgement unit includes:

a judgement time setting unit operable to receive a setting of a predetermined time according to a speed of input of handwriting of the user, the time judgement unit judging that the input of the immediately preceding handwritten character string is complete when the input thereof ceases for at least the predetermined time.

6. A handwritten character recognition apparatus according to claim 1, wherein the input completion judgement unit includes:

a stroke area judgement unit operable to judge that the input of the immediately preceding character string is complete when a first coordinate of a stroke thereof is in a second area which is an area at the opposite side of the character string input area to the first area.

7. A handwritten character recognition apparatus according to claim 6, further comprising:

a display unit, positioned under a transparent tablet which makes up the character string input area, operable to successively display strokes by linking the coordinates of each coordinate string detected by the coordinate string detection unit by line segments, and

an area display control unit operable to control a display state of the display unit so as make the first area and the second area visually recognizable.

8. A handwritten character recognition apparatus according to claim 1, further comprising:

a display unit operable to display a stroke by linking the coordinates of each coordinate string successively detected by the coordinate string detection unit, and

an erasing unit operable to erase all strokes that make up the immediately preceding handwritten character string when the input completion judgement unit judges the input thereof to be complete.

9. A handwritten character recognition apparatus according to claim 1, further comprising:

a display unit, positioned under a transparent tablet which makes up the character string input area, operable to successively display strokes by linking coordinates detected by the coordinate value detection unit by line segments, the coordinate string detection unit being a transparent tablet, and

a first area display control unit operable to control a display state of the display unit so as make the first area and the second area visually recognizable.

10. A handwritten character recognition apparatus having a character string input area of a size that allows a plurality of characters to be handwritten thereon for a user to input a handwritten character string, comprising:

a coordinate string detection unit operable to detect a coordinate string of each stroke that makes up an input handwritten character string,

a display unit, positioned under a transparent tablet which makes up the character string input area, operable to successively display strokes by linking coordinates detected by the coordinate value detection unit by line segments, the coordinate string detection unit being a transparent tablet,

a first line segment erasing unit operable to erase line segments displayed in a judgement area which is an area a predetermined distance apart from the last coordinate of a stroke detected by the coordinate string detection unit in a direction towards the side of the character string input area where writing of the handwritten character string starts,

an input completion judgement unit operable to judge, when the coordinate string detection unit detects the first coordinate of a stroke in the judgement area, that an input of an immediately preceding handwritten character string is complete,

a second line segment erasing unit operable to erase remaining line segments from the character string input area, excluding the line segments in the judgement area, and

a segmentation recognition unit operable to segment, when the input completion detection unit judges the input to be complete, stroke strings for each character from all the strokes of the immediately preceding handwritten character string, recognize each character, and output a character string which is a recognition result.

11. A program for use with a handwritten character recognition apparatus having a character string input area of a size that allows a plurality of characters to be handwritten thereon for a user to input a handwritten character string, the program realizing on a computer:

a coordinate string detection unit operable to detect a coordinate string of each stroke that makes up an input handwritten character string,

an input completion judgement unit operable to judge, when a first coordinate of one of the strokes is detected in a first area which is at a side of the character string input area where writing of the handwritten character string starts, whether an input of an immediately preceding handwritten character string is complete, and

a segmentation recognition unit operable to segment, when the input completion detection unit judges the input to be complete, stroke strings for each character from all the strokes of the immediately preceding handwritten character string, recognize each character, and output a character string which is a recognition result.

12. A computer-readable recording medium for use with a handwritten character recognition apparatus having a character string input area of a size that allows a plurality of characters to be handwritten thereon for a user to input a handwritten character string, the medium recording a program that realizes on a computer:

a coordinate string detection unit operable to detect a coordinate string of each stroke that makes up an input handwritten character string,

an input completion judgement unit operable to judge, when a first coordinate of one of the strokes is detected in a first area which is at a side of the character string input area where writing of the handwritten character string starts, whether an input of an immediately preceding handwritten character string is complete, and

a segmentation recognition unit operable to segment, when the input completion detection unit judges the input to be complete, stroke strings for each character from all the strokes of the immediately preceding handwritten character string, recognize each character, and output a character string which is a recognition result.