JPH0855185A - Character recognition device - Google Patents

Abstract

PURPOSE:To provide a character recognition device which accurately and speedily decides a line area and is high in the reliability of character recognition. CONSTITUTION:The character recognition device is equipped with a character integration strength setting part 13 which sets a reference value for deciding a line area, an integration distance calculating means 14 which calculates an integration distance by multiplying the most frequent value of character intervals detected by a character interval and line interval detecting means 6 by the reference value set by the character integration strength setting part 13, and a recognition information storage part 16 which stores the reference value set by the character integration strength setting part 13 and the integration distance calculated by the integration distance calculating means 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention captures a document image by using an optical means such as a scanner and converts the captured image data into characters, figures, tables, etc. in order to create a database of printed documents and reuse the documents. The present invention relates to a character recognition device that extracts a region for each attribute and performs a recognition process according to each attribute.

[0002]

2. Description of the Related Art In recent years, image data including information such as characters, figures and tables of documents has been often processed by a character recognition device. Using this character recognition device, the character information represented by the image data is converted into code information such as JIS code (which is called a recognition result in the character recognition device) and processed.

A conventional character recognition device will be described below. FIG. 7 is a configuration block diagram showing a configuration of a conventional character recognition device. In FIG. 7, 1 is an image input unit for inputting image data including character data, 2 is an image storage unit for storing the image data input to the image input unit 1, and 3 is a recognition dictionary unit for storing graphic features of characters. Reference numeral 4 denotes a circumscribing rectangle detecting means for detecting a circumscribing rectangle circumscribing the black pixel area from the image data stored in the image storage unit 5. Reference numeral 5 denotes a character candidate rectangle from the circumscribing rectangle detected by the circumscribing rectangle detecting means 4. A character candidate rectangle detecting means, 6 is a character interval and a line interval detecting means for detecting a character interval and a line interval between the character candidate rectangles detected by the character candidate rectangle detecting means 5, and 7 is a character interval and a line interval detecting means 6. When the detected character spacing is shorter than a predetermined integrated distance, the line area determination means determines that the line areas are the same, and 8 detects the character area from the line area determined by the line area determination means 7. Character region detection means, 9
Is a character recognizing means for obtaining a recognition result by collating the character area detected by the character area detecting means 8 with the graphic feature stored in the recognition dictionary unit 3, and 10 is a circumscribing rectangle detecting means 4 and a character candidate rectangle detecting means. Means 5, character spacing / line spacing detection means 6, line area determination means 7, and character area detection means 8
And a character recognizing means 9, and a control section 11 having a circumscribing rectangle detected by the circumscribing rectangle detecting means 4, a character candidate rectangle detected by the character candidate rectangle detecting means 5, a character spacing, and a line spacing detecting means 6. The character spacing and the line spacing detected by the line area and the line area determined by the line area determination means 7,
A recognition information storage unit for storing the character area detected by the character area detection unit 8 and the recognition result collated by the character recognition unit 9, and 12 is a recognition result for outputting the recognition result collated by the character recognition unit 9. It is an output part.

The operation of the character recognizing device having the above structure will be described below. First, image data including character data is input to the image input unit 1 such as a scanner and stored in the image storage unit 2. Next, a rectangle circumscribing a block in which black pixels of the binary data stored in the image storage unit 2 are connected by the circumscribing rectangle detector 4 (hereinafter referred to as a circumscribing rectangle).
The coordinates are detected and stored in the recognition information storage unit 11. Next, the character candidate rectangle detecting means 5 detects a rectangle having a relatively large circumscribing rectangle detected by the circumscribing rectangle detecting means 4 as a figure candidate rectangle, and detects the other rectangles as a character candidate rectangle, and determines the coordinates of the figure candidate rectangle and the character candidate rectangle. It is stored in the recognition information storage unit 11. Next, the character spacing and line spacing detection means 6 measures the horizontal and vertical spacings of the character candidate rectangles to detect the character spacing and line spacing, and recognizes the character spacing and line spacing.
Store in 1. Next, the character spacing is smaller than this value based on the value obtained by multiplying the mode value of the character spacing detected by the line area determination means 7 and the character spacing detected by the line spacing detection means 6 by the integrated distance which is a fixed value. Objects are judged to be in the same line area,
The row area is stored in the recognition information storage unit 11. Next, the character area detection unit 8 detects a character area from the line area determined by the line area determination unit 7, and stores the character area in the recognition information storage unit 11. Next, the character recognition unit 9 collates the character region detected by the character region detection unit 8 with the graphic feature stored in the recognition dictionary unit 3 to obtain a recognition result, and the recognition result is stored in the recognition information storage unit. It is stored in 11. Next, the recognition result output unit 12 outputs the recognition result collated by the character recognition means 9. FIG. 8 is a diagram showing a conventional determination of a line area when a character spacing is large, and FIG. 9 is a diagram showing a conventional determination of a line area when a character spacing is small.

[0005]

However, the above-described conventional character recognition device has a problem that, as shown in FIG. 8, if there is a sentence having a long character interval, it is not determined to be the same line area. In addition, as shown in FIG. 9, even when it is necessary to determine a different line area when the character spacing is short,
There is a problem that it is determined that they are in the same line area.

Further, if the line area is erroneously determined, it is not an accurate sentence when a character-recognized document is edited, so that there is a problem that the editing is not normally performed.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a character recognition device which is accurate and quick in determining a line area and has high reliability in character recognition.

[0008]

In order to achieve this object, a character recognition apparatus according to claim 1 of the present invention is an image input section for inputting image data including character data, and an image input section. An image storage unit for storing the image data, a recognition dictionary unit for storing the graphic features of the character, a circumscribing rectangle detecting means for detecting a circumscribing rectangle circumscribing the black pixel region from the image data stored in the image storage unit, A character candidate rectangle detecting means for detecting a character candidate rectangle from the circumscribing rectangle detected by the circumscribing rectangle detecting means, and a character interval and a line for detecting a character interval and a line interval between the character candidate rectangles detected by the character candidate rectangle detecting means. If the character spacing and the character spacing detected by the line spacing detecting means are shorter than the integrated distance, the line area determining means determines the same line area, and the line area determining means determines the same. A character area detecting means for detecting a character area from the line area, and a character recognizing means for obtaining a recognition result by collating the character area detected by the character area detecting means with the graphic feature stored in the recognition dictionary section, The circumscribing rectangle detected by the circumscribing rectangle detecting means, the character candidate rectangle detected by the character candidate rectangle detecting means, the character spacing, the character spacing and line spacing detected by the line spacing detecting means, and the line determined by the line area determining means An area, a character area detected by the character area detecting unit, and a recognition information storage unit that stores the recognition result collated by the character recognition unit; and a recognition result output unit that outputs the recognition result collated by the character recognition unit, A character recognition device including: a character integrated strength setting unit that sets a reference value for determining a line area; An integrated distance calculating means for calculating the integrated distance by multiplying the mode value of the character spacing by the reference value set by the character integrated strength setting unit, and the reference value set by the character integrated strength setting unit, and the integrated distance calculation And a recognition information storage unit that stores the integrated distance calculated by the means.

[0009]

With this configuration, the character integrated strength setting unit sets the reference value for determining the line area, and the integrated distance calculating means sets the character integrated strength to the mode value of the character spacing and the character spacing detected by the line spacing detecting means. Since the integrated distance calculated by multiplying the reference value set by the setting unit can be calculated, and the reference value set by the character integrated strength setting unit and the integrated distance calculated by the integrated distance calculating unit can be stored in the recognition information storage unit. The user can determine the integrated distance for deciding the row area by observing the state of the image data. Therefore, since the line area can be accurately determined, highly reliable character recognition can be performed.

[0010]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram showing the configuration of a character recognition device in one embodiment of the present invention, and FIG. 2 is a device block diagram showing the configuration of a character recognition device in one embodiment of the present invention.

In FIG. 1, 1 is an image input unit, 2 is an image storage unit, 3 is a recognition dictionary unit, 4 is a circumscribing rectangle detecting unit, 5 is a character candidate rectangle detecting unit, 6 is a character interval and line interval detecting unit, Reference numeral 7 is a line area determination unit, 8 is a character area detection unit, 9 is a character recognition unit, and 12 is a recognition result output unit. These are the same as in the conventional example, and the same reference numerals are given and the description thereof is omitted.

Reference numeral 13 is a character integrated strength setting unit for setting a reference value for judging a line area, and 14 is set by the character integrated strength setting unit 13 for the character interval and the mode value of the character interval detected by the line interval detecting means 6. Integrated distance calculating means for calculating an integrated distance by multiplying the determined reference value, 15 is a circumscribing rectangle detecting means 4
, Character candidate rectangle detecting means 5, character spacing / line spacing detecting means 6, integrated distance calculating means 14, and line area determining means 7.
And a character area detecting unit 8 and a character recognizing unit 9, and 16 is a reference value set in the character integrated strength setting unit 13, a circumscribing rectangle detected by the circumscribing rectangle detecting unit 4, and a character. The character candidate rectangle detected by the candidate rectangle detecting means 5, the character spacing, the character spacing and line spacing detected by the line spacing detecting means 6, the integrated distance calculated by the integrated distance calculating means 14, and the line area determining means. 7 is a recognition information storage unit that stores the line area determined by 7, the character area detected by the character area detection unit 8, and the recognition result collated by the character recognition unit 9.

In FIG. 2, 17 is a scanner which is the image input unit 1, 18 is a CRT which is a recognition result output unit 12, 1
Reference numeral 9 is a keyboard for giving a command to the central processing unit 21 from the outside, 20 is a mouse for giving a command to the central processing unit 21 from the outside, 21 is a scanner 17, a CRT 18, a keyboard 19, a mouse 20 and a random number.・
Central processing unit (CP which controls access memory 25)
(Abbreviated as U), 22 is an image storage unit for storing image data,
Reference numeral 23 is a recognition dictionary unit that stores graphic features of characters, 24 is a recognition information storage unit that stores recognition information obtained by each means in the control unit 15, and 25 is an image storage unit 22 and a recognition dictionary unit 2.
A random access memory having 3 and a recognition information storage unit 24 is a system bus connecting the scanner 17, the CRT 18, the keyboard 19, the mouse 20, the central processing unit 21, and the random access memory 25.

The operation of the character recognition device configured as described above will be described below with reference to the drawings. FIG. 3 is a flowchart showing the operation of the character recognition device in one embodiment of the present invention, and FIG. 4 is a diagram showing a CRT screen for character integrated strength setting in one embodiment of the present invention. First, as shown in FIG. 4, in the character integrated strength setting unit 13, the character integrated strength is strong (hereinafter, CHAR_COMB1).
Called. Here, CHAR_COMB1 = 2, ordinary (hereinafter referred to as CHAR_COMB2).
MB = 12/5), weak (hereinafter referred to as CHAR_COMB3. Here, one of CHAR_COMB3 = 3) is determined (S1). Next, the image data including the character data is read by the image input unit 1 and then stored in the image storage unit 2 (S2). Next, the image data stored in the image storage unit 2 is reduced (S3). Next, a circumscribing rectangle that circumscribes the black pixel area of the image data stored in the image storage unit 2 is extracted, and the upper left coordinates (x ₁ , y ₁ ) and the lower right coordinates (x ₂ , y ₂ ) of the circumscribing rectangle are extracted. ) Is stored as circumscribed rectangle information in the recognition information storage unit 16 (S4). Next, the aspect ratio of the circumscribed rectangle is a threshold value FD_RATIO (here, FD_RATIO = 3).
If 0 or more, the circumscribed rectangle is set as the ruled line candidate area. Further, a portion where the coordinates intersect between the ruled line candidate areas is searched, and the intersected ruled line candidate areas are integrated into a table candidate area. The long side of the circumscribed rectangle is the threshold CHAR_MAX (here, CHAR_MAX
= 100) or more and the black pixel density of the circumscribed rectangle is a threshold value PER_DIAG_MIN (here, PER_DIAG).
If _MIN = 15) or less, the circumscribed rectangle is set as the figure candidate area. The long side of the circumscribed rectangle is greater than or equal to the threshold CHAR_MAX, and the black pixel density of the circumscribed rectangle is the threshold PER_DIAG.
If _MAX (here, PER_DIAG_MAX = 80) or more, the circumscribed rectangle is set as the image candidate area. The circumscribing rectangles other than the ruled line candidate area, the table candidate area, the figure candidate area, and the image candidate area are set as the character candidate rectangles, and each area is stored in the recognition information storage unit 16 (S5). Next, the horizontal spacing between character candidate rectangles (herein referred to as character spacing) and the vertical spacing between character candidate rectangles (herein referred to as line spacing) are detected and stored in the recognition information storage unit 16 (S).
6). Next, CHAR_COMB is set to the mode of the character spacing.
1, CHAR_COMB2, or CHAR_COMB
The set distance of 3 is multiplied by 1 to calculate the integrated distance, which is stored in the recognition information storage unit 16 (S7). Next, the character candidate rectangle whose character interval is shorter than the integrated distance is determined to be in the same line area, and is stored in the recognition information storage unit 16 (S8). Next, the character areas on a line-by-line basis are integrated from the line areas to detect the character areas, which are stored in the recognition information storage unit 16 (S9). Next, the character area detected by the character area detecting unit 8 is collated with the graphic feature stored in the recognition dictionary section 3 to obtain a recognition result, which is stored in the recognition information storage section 16 (S10). Next, the recognition result collated by the character recognition means 7 is output (S11), and the process ends.

An example of a circumscribed rectangle is shown below. 5 is a diagram showing an example of image data in one embodiment of the present invention, and FIG. 6 is a diagram showing a circumscribed rectangle of the image data shown in FIG. 5 in one embodiment of the present invention. The circumscribing rectangle detected by the circumscribing rectangle detecting means 4 from the example of the image data shown in FIG. 5 is shown in FIG.
It was shown to. In FIG. 6, K1 to K9 are circumscribed rectangles.

As described above, according to the present embodiment, the character integrated strength setting unit 13 for setting the reference value for determining the line area,
Integrated distance calculating means 1 for calculating the integrated distance by multiplying the mode of the character spacing detected by the character spacing / line spacing detecting means 6 by the reference value set by the character integrated strength setting unit 13.
4 and the reference value set by the character integrated strength setting unit 13,
By providing the recognition information storage unit 16 capable of storing the integrated distance calculated by the integrated distance calculating unit 14, the user can observe the state of the image data and determine the reference value for determining the line area. The line area can be accurately determined. Therefore, even when the character data is edited, the character data can be recognized as an accurate sentence. Further, when recognizing a character, it is possible to recognize an accurate and highly reliable character.

[0018]

As described above, according to the present invention, a character integrated strength setting unit for setting a reference value for determining a line area, a character interval,
The integrated distance calculating means for calculating the integrated distance by multiplying the mode value of the character spacing detected by the line spacing detecting means by the reference value set by the character integrated strength setting section, and the integrated distance setting section set by the character integrated strength setting section By providing the reference value and the recognition information storage section capable of storing the integrated distance calculated by the integrated distance calculating means, the user can determine the reference value for judging the line area by observing the state of the image data. Therefore, the line area can be accurately determined. Therefore, even when the character data is edited, the character data can be recognized as an accurate sentence. Further, it is possible to achieve an excellent character recognition device capable of performing accurate and highly reliable character recognition when recognizing characters.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of a character recognition device according to an embodiment of the present invention.

FIG. 2 is a device block diagram showing a configuration of a character recognition device according to an embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the character recognition device in the embodiment of the present invention.

FIG. 4 is a diagram showing a CRT screen for character integrated strength setting according to an embodiment of the present invention.

FIG. 5 is a diagram showing an example of image data according to an embodiment of the present invention.

FIG. 6 is a diagram showing a circumscribed rectangle of the image data shown in FIG. 5 according to an embodiment of the present invention.

FIG. 7 is a configuration block diagram showing a configuration of a conventional character recognition device.

FIG. 8 is a diagram showing determination of a line area when a conventional character spacing is large.

FIG. 9 is a diagram showing determination of a line area when the character spacing is small in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 image input section 2 image storage section 3 recognition dictionary section 4 circumscribing rectangle detection means 5 character candidate rectangle detection means 6 character spacing, line spacing detection means 7 line area determination means 8 character area detection means 9 character recognition means 10 control section 11 recognition Information storage unit 12 Recognition result output unit 13 Character integrated strength setting unit 14 Integrated distance calculating unit 15 Control unit 16 Recognition information storage unit 17 Scanner 18 CRT 19 Keyboard 20 Mouse 21 Central processing unit 22 Image storage unit 23 Recognition dictionary unit 24 Recognition information Storage 25 Random access memory 26 System bus

Claims (1)

[Claims] 1. An image input section for inputting image data including character data, an image storage section for storing the image data input to the image input section, and a recognition dictionary section for storing graphic features of characters. A circumscribing rectangle detecting means for detecting a circumscribing rectangle circumscribing a black pixel area from the image data stored in the image storage section, and a character candidate for detecting a character candidate rectangle from the circumscribing rectangle detected by the circumscribing rectangle detecting means. Rectangle detecting means, character spacing for detecting the character spacing and line spacing between the character candidate rectangles detected by the character candidate rectangle detecting means, line spacing detecting means, and the character spacing, the line spacing detecting means A line area determination unit that determines that the line areas are the same when the character spacing is shorter than the integrated distance,
A character area detecting unit for detecting a character area from the line area determined by the line area determining unit; the character area detected by the character area detecting unit; and the graphic feature stored in the recognition dictionary unit. A character recognizing means for obtaining a recognition result by collation, the circumscribing rectangle detected by the circumscribing rectangle detecting means, the character candidate rectangle detected by the character candidate rectangle detecting means, the character spacing, line spacing detecting means The detected character spacing and line spacing, the line area determined by the line area determination means, the character area detected by the character area detection means, and the recognition result collated by the character recognition means. A character provided with a recognition information storage unit for storing and a recognition result output unit for outputting the recognition result collated by the character recognition means. And a character integrated strength setting unit that sets a reference value for determining the line area, and the character integrated strength setting unit that sets the mode value of the character spacing detected by the character spacing and line spacing detection unit to the mode. Integrated distance calculating means for calculating the integrated distance by multiplying the reference value set in, the reference value set in the character integrated strength setting unit, and the integrated distance calculated by the integrated distance calculating means And a recognition information storage section that stores the character recognition apparatus.