CHARACTER STRING RECOGNITION METHOD AND DEVICE

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an electrical structure of a character string recognition device in accordance with an embodiment of the present invention;

FIG. 2 is a flow chart showing a schematic flow of a character string recognition method in accordance with an embodiment of the present invention;

FIG. 3 is a flow chart showing a detailed flow of a line cutout step in the flow chart shown in FIG. 2;

FIG. 4 is a view showing an example of image data when characters printed on an OCR character record region of a record carrier (see FIG. 1) are imaged;

FIG. 5 is a view showing a first projection data when image data shown in FIG. 4 are projected in a character string direction;

FIG. 6 is a view showing another example of image data when characters printed on the OCR character record region of the record carrier (see FIG. 1) are imaged;

FIG. 7 is a view showing a first projection data when image data shown in FIG. 6 are projected in the character string direction;

FIG. 8 is a view showing image data in which character strings are divided into five segments of “A” through “E”;

FIG. 9 is a view showing a first projection data when image data (for respective segments) shown in FIG. 8 are projected in the character string direction;

FIG. 10 is a flow chart showing a detailed flow of a character cutout step in the flow chart shown in FIG. 2;

FIG. 11 is a view showing another example of image data when characters printed on the OCR character record region of the record medium (see FIG. 1) are imaged;

FIG. 12 is a view where a second projection data of the segments “A” through “E” are connected;

FIG. 13 is a view showing an example of image data of characters which are included in a character string;

FIG. 14 is a view showing an example of a second projection data which are obtained by perpendicularly projecting the image data shown in FIG. 13;

FIG. 15 is a view showing another example of a second projection data which are obtained by perpendicularly projecting the image data shown in FIG. 13; and

FIG. 16 is a view showing image data of a character “<” which is included in a 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;calculating, in a first step, a first projection data of the image data in a direction of the character string while shifting in a perpendicular direction which is perpendicular to a direction of the character string; anddetecting, in a second step, a position of the character string in the perpendicular direction on a basis of the first projection data which are obtained through the first step;wherein, 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.

2. The character string recognition method according to claim 1, further comprising the steps of: calculating, in a third step, a second projection data in the segment in the perpendicular direction 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; andobtaining, in a fourth step, a position where the second projection data through the third step exceeds a threshold value as a boundary position of a character included in the character string;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.

3. The character string recognition method according to claim 2, 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.

4. A character string recognition device comprising: a character string recognition section for recognizing a character string on a medium by using the following character string recognition method as follows:imaging a character string on a medium to obtain image data;calculating, in a first step, a first projection data of the image data in a direction of the character string while shifting in a perpendicular direction which is perpendicular to a direction of the character string; anddetecting, in a second step, a position of the character string in the perpendicular direction on a basis of the first projection data which are obtained through the first step;wherein, 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.

5. The character string recognition device according to claim 4, wherein the character string recognition section further performs the character string recognition method as follows: calculating, in a third step, a second projection data in the segment in the perpendicular direction 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; andobtaining, in a fourth step, a position where the second projection data through the third step exceeds a threshold value as a boundary position of a character included in the character string;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.

6. The character string recognition device according to claim 5, wherein the method requires that 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.