Handwritten character recognition apparatus

• US 6,931,153 B2
• Filed: 04/19/2001
• Issued: 08/16/2005
• Est. Priority Date: 04/20/2000
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nakao, Ichiro, Ito, Yoshikatsu
• Primary Examiner(s): COUSO, YON JUNG
• Application Number:
  US09/837,293
• Publication Number:
  US 20020009226A1
• Time in Patent Office: 1,580 Days
• Field of Search: 382/187, 382/188, 382/189, 382/177, 382/185, 382/186, 382/314, 382/179, 345/179, 345/180
• US Class Current: 382/188
• 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 portable 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, said apparatus comprising:

a coordinate string detection unit that detects a coordinate string of each stroke that makes up an input handwritten character string in the character string input area, the character string input area being composed of a single frame in which one or more handwritten characters are recognized;

an input completion judgement unit that judges, 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 that segments, when said 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, recognizes each character, and outputs a character string which is a recognition result;

wherein said input completion judgment unit includes;

a first coordinate judgement unit that judges, 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.

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

a display unit that successively displays strokes by linking coordinates detected by said coordinate value detection unit by line segments; and

a first area display control unit that controls a display state of said display unit so as make the first area and the second area visually recognizable,

wherein said coordinate string detection unit comprises a transparent tablet, and

wherein said display unit is positioned under said display tablet.

3. A portable handwritten character recognition apparatus according to claim 1,

wherein the input completion judgement unit further includes an X1 setting unit that receives a value of X1 according to a size of a handwritten character written by the user, and

wherein said first coordinate judgement unit judges according to the received value of X1.

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

an input time measurement unit that measures 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 that judges, 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 potable handwritten character recognition apparatus according to claim 4, wherein said input completion judgement unit further includes:

a judgement time setting unit that receives 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 potable handwritten character recognition apparatus according to claim 1, wherein the input completion judgement unit includes:

a stroke area judgement unit that judges 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 portable 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, that successively displays strokes by linking the coordinates of each coordinate string detected by said coordinate string detection unit by line segments; and

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

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

a display unit that display a stroke by linking the coordinates of each coordinate string successively detected by said coordinate string detection unit; and

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

9. 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 including apparatus readable instructions capable of instructing a handwritten character recognition apparatus to:

detect a coordinate string of each stroke that makes up an input handwritten character string in the character string input area, the character string input area being composed of a single frame in which one or more handwritten characters are recognized;

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 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; and

segment, when the input is judged 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.

10. 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 having recorded thereon, apparatus readable instructions capable of instructing a handwritten character recognition apparatus to:

detect a coordinate string of each stroke that makes up an input handwritten character string in the character string input area, the character string input area being composed of a single frame in which one or more handwritten characters are recognized;

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 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; and

segment, when the input is judged 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.