Character string recognition method and device

• US 7,949,187 B2
• Filed: 03/29/2007
• Issued: 05/24/2011
• Est. Priority Date: 03/30/2006
• Status: Expired due to Fees

• Current Assignee: Nidec Sankyo Corporation (Nidec Corporation)
• Original Assignee: Nidec Sankyo Corporation (Nidec Corporation)
• Inventors: Nakamura, Hiroshi
• Primary Examiner(s): Le; Vu
• Assistant Examiner(s): Park; Soo Jin
• Application Number:
  US11/693,139
• Publication Number:
  US 20070230784A1
• Time in Patent Office: 1,517 Days
• Field of Search: 382/174, 382/177, 382/171, 382/172, 382/185, 382/187, 382/188, 358/1.11, 358/3.31
• US Class Current: 382/177
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/1478 of characters or characters lines

Abstract

A character string recognition method for recognizing a character string may include a first step in which a first projection data of image data are calculated in a direction of the character string and a second step in which a position of the character string is detected on the basis of the first projection data. In the first step, the image data are divided into a plurality of segments in the direction of the character string and projection in the segment is calculated. The method may further include a third step in which a second projection data in the segment are calculated on the basis of the position of the character string and a fourth step in which a position where the second projection data exceeds a threshold value is detected as a boundary position of a character, and the threshold value may be changed according to pixel number between both ends of the character string.

Claims

1. A character string recognition method for recognizing a character string comprising the steps of:

imaging a character string on a medium to obtain image data;

a first step in which;

a first projection data of the image data are calculated in a direction of the character string while shifting in a perpendicular direction which is perpendicular to a direction of the character string; and

the image data are divided into a plurality of segments in the direction of the character string and projection in each of the plurality of segments is calculated;

a second step in which a position of the character string in the perpendicular direction is detected on a basis of the first projection data which are obtained through the first step;

a third step in which a second projection data in the segment in the perpendicular direction are calculated on a basis of the position of the character string which is detected through the second step while shifting in the direction of the character string; and

a fourth step in which a position where the second projection data obtained through the third step exceeds a threshold value is detected as a boundary position of a character included in the character string;

wherein the threshold value is made larger as the pixel number between both ends of the character string increases and the threshold value is made smaller as the pixel number between both ends of the character string decreases.

2. The character string recognition method according to claim 1, further comprising the steps of:

wherein the threshold value is changed according to pixel number between both ends of the character string which are detected by the second projection data between a lower limit of the threshold value and an upper limit of the threshold value.

3. A character string recognition device comprising:

a character string recognition section for recognizing a character string on a medium by using the character string recognition method as set forth in claim 1.

4. The character string recognition device according to claim 3;

wherein the character string recognition section is further configured to change the threshold value according to pixel number between both ends of the character string which are detected by the second projection data between a lower limit of the threshold value and an upper limit of the threshold value.