JPH0896080A - Optical character reader - Google Patents

Abstract

PURPOSE: To reduce the capacity of a dictionary memory and to reduce the difference of the matching processing time of each character pattern, regardless of the storage order in the dictionary memory. CONSTITUTION: A character pattern division part 12 divides the character pattern which is temporarily held in a character pattern memory 11 into a preliminarily set division number and each divided character pattern is stored in a divided character pattern memory 13. In a divided dictionary pattern memory 14, the divided dictionary pattern that a dictionary pattern is preliminarily divided into this division number is stored. A matching part 15 performs the matching processing of each divided character pattern divided in the character pattern division part 12 and the divided dictionary pattern of the division dictionary pattern memory 14. A judging result determination part 16 performs the judgment of the character pattern segmented based on the result of matching processing in the matching part 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical character reading device, and more particularly to an optical character reading device for reading and determining printed characters from a character image.

[0002]

2. Description of the Related Art Conventionally, an optical character reading device has an image input circuit for reading and outputting typed characters from character image data,
It is composed of a character cutout circuit that cuts out each typed character from the input image data, and a character determination circuit that determines each typed character from the cut out character pattern.

Here, the character determination circuit, as shown in FIG. 6, has a character pattern memory 41 for storing the character pattern cut out by a character cutting circuit (not shown), and a dictionary pattern having the same area as the input character pattern. Dictionary memory 42 for storing
And a matching unit 43 that matches the character pattern of the character pattern memory 41 with the dictionary pattern of the dictionary memory 42, and a determination result determination unit 44 that determines the character pattern based on the matching result of the matching unit 43. ing.

The character pattern cut out by the character cutting circuit is temporarily stored in the character pattern memory 41, and the matching unit 43 performs matching with the dictionary pattern stored in the dictionary memory 42.

This matching is sequentially performed in the order in which the dictionary patterns stored in the dictionary memory 42 are stored, and it is determined from the matching results which character pattern the extracted character pattern corresponds to.

[0006]

In the above-mentioned conventional optical character reading device, since the shape of a certain specific character is locally different, when a reading character type is added, a dictionary pattern of different character types and the same character is added. In most cases, the shapes match each other, and the area overlap amount, that is, the data overlap amount, of the matching portion is wasted.

Further, the character determination circuit must repeat the collation process for the character image stored in the character pattern memory according to the collation dictionary storage fixed order always stored in the dictionary memory until the specified threshold is satisfied from the first dictionary. Since it is necessary to perform matching with more dictionary patterns as the storage fixed order becomes later, it takes a lot of time to perform the character matching process.

Therefore, an object of the present invention is to solve the above problems and to reduce the capacity of the dictionary memory, and reduce the difference in collation processing time of each character pattern regardless of the storage order in the dictionary memory. An object of the present invention is to provide an optical character reading device that can be used.

[0009]

An optical character reader according to the present invention is an optical character reader that cuts out a print character read from character image data for each character and determines the character pattern of the cut out print character. Corresponding to the output of the dividing unit and the divided portion thereof, the dividing unit dividing the cut-out type character into a preset division number, the storage unit storing the division dictionary pattern divided in the division number in advance. Means for performing superposition with a divided dictionary pattern, means for extracting candidate characters for each divided portion from the result of the superposition, and characters for the print characters based on the extracted candidate characters for each divided portion. And a determining means for determining the pattern.

Another optical character reading device according to the present invention comprises, in addition to the above-mentioned structure, a holding means for holding each of the divided portions divided by the dividing means.

[0011]

The character pattern of the print characters cut out by the character cutting circuit is divided into a preset number of divisions by the character pattern division unit, and each of the divided character patterns is divided into a predetermined number of divisions in the division dictionary pattern memory. The matching unit performs the matching process with the divided dictionary pattern.

The character pattern of the above-mentioned print characters is judged based on the judgment result candidates of the respective divided character patterns obtained from this collation processing.

As a result, it is possible to avoid overlapping of similar portions between the collation dictionaries, so that it is possible to reduce the collation dictionary data and to perform the same character determination as before the collation dictionary data amount reduction.

Therefore, the duplicate matching of similar portions between the matching dictionaries is eliminated, and the difference in matching processing time of each character pattern is reduced regardless of the storage order in the dictionary memory.

[0015]

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, the character determination circuit 1 includes a character pattern memory 11, a character pattern dividing unit 12, a divided character pattern memory 13, and a divided dictionary pattern memory 14.
And a matching unit 15 and a determination result determining unit 16.

The character pattern memory 11 temporarily holds the character pattern cut out by a character cutting circuit (not shown) and outputs it to the character pattern dividing unit 12. Character pattern division unit 1
Reference numeral 2 divides the character pattern temporarily stored in the character pattern memory 11 into a preset number of divisions, and stores each divided character pattern in the divided character pattern memory 13.

The divided dictionary pattern memory 14 stores a divided dictionary pattern in which the dictionary pattern is divided into the above-mentioned divided numbers in advance, that is, each divided portion of the dictionary pattern and a candidate character (category) including the divided portion. .

If, for example, the character pattern to be determined is divided into five stages in the vertical direction by the character pattern dividing unit 12, the matching unit 15 performs matching between the character patterns and the divided portions located at the same number of stages, and the matching is performed. The candidate character obtained from is output to the determination result determination unit 16.

The determination result determining unit 16 determines which candidate character the cut-out character pattern corresponds to, based on the candidate characters obtained by the matching in each stage of the matching unit 15, and outputs the determination result. To do.

FIG. 2 is a block diagram showing the system configuration of an embodiment of the present invention. In the figure, an optical character reading apparatus according to an embodiment of the present invention includes an image input circuit 2 for reading and outputting typed characters from character image data, a character cutout circuit 3 for cutting out each typed character from the input image data, and a cutout circuit. It is composed of a character determination circuit 1 which determines each printed character from the output character pattern. Here, the character determination circuit 1 is configured as described above.

FIG. 3 is a diagram showing an example of character pattern division according to an embodiment of the present invention. In the figure, the character pattern is divided into five stages in the vertical direction by the character pattern division unit 12,
It is shown that the divided character patterns a to e that have been divided are sent to the matching unit 15 via the divided character pattern memory 13.

That is, the character pattern "8" is vertically divided by the character pattern division unit 12 into five stages, and the divided first-stage divided character pattern a, the second-stage divided character pattern b, and the third-stage divided character pattern. The divided character pattern c, the fourth divided character pattern d, and the fifth divided character pattern e are stored in the divided character pattern memory 13, respectively.

Each of the divided character patterns a to e stored in the divided character pattern memory 13 is sent to the matching unit 15, and the matching unit 15 sequentially outputs the divided character pattern a of the first stage to the divided character pattern e of the fifth stage. Matching is performed with the divided dictionary pattern.

FIG. 4 is a diagram showing an example of dictionary pattern division according to an embodiment of the present invention. In the figure, the divided dictionary pattern a of the first stage when the dictionary pattern of the print characters (numerals) “0” to “9” is divided into five stages in the vertical direction as above.
1 to a4 are shown.

In this case, the print characters "0", "2",
Since "3", "5", "7", "8", and "9" include the divided dictionary pattern a1, the divided dictionary pattern memory 14 has "0" as a category (candidate character),
“2”, “3”, “5”, “7”, “8”, and “9” are stored in association with each other.

Since the print character "1" includes the divided dictionary pattern a2, the divided dictionary pattern memory 1
4 is stored in association with “1” as a category.

Furthermore, since the print character "4" includes the divided dictionary pattern a3, "4" is stored as a category in the divided dictionary pattern memory 14 in association with each other.

Furthermore, since the print character "6" includes the divided dictionary pattern a4, "6" is stored in the divided dictionary pattern memory 14 in association with the category.

FIG. 5 is a diagram showing an example of a character determination procedure according to an embodiment of the present invention. The figure shows a character determination procedure for determining the type character "8" shown in FIG.

That is, as the first pattern of the dictionary pattern for the first stage of the divided dictionary pattern memory 14, the divided dictionary pattern a1 has the categories "0", "2", "3",
It is stored in association with "5", "7", "8", and "9".

As the second pattern of the first-stage dictionary pattern, the divided dictionary pattern a2 is stored in association with the category "1".

Further, as the third pattern of the first-stage dictionary pattern, the divided dictionary pattern a3 is stored in association with the category "4".

Furthermore, as the fourth pattern of the first-stage dictionary pattern, the divided dictionary pattern a4 is stored in association with the category "6".

As the first pattern of the second-stage dictionary pattern of the divided dictionary pattern memory 14, the divided dictionary pattern b is used.
1 is stored in association with categories “1”, “2”, “3”, and “7”.

As the second pattern of the second-stage dictionary pattern, the divided dictionary pattern b2 is category "4",
It is stored in association with “8”, “9”, and “0”.

Further, as the third pattern of the second-stage dictionary pattern, the divided dictionary pattern b3 is the category "5",
It is stored in association with “6”.

As the first pattern of the third-stage dictionary pattern of the divided dictionary pattern memory 14, the divided dictionary pattern c is used.
1 is category “2”, “3”, “4”, “5”,
It is stored in association with "6", "8", and "9".

As the second pattern of the third-stage dictionary pattern, the divided dictionary pattern c2 is category "1",
It is stored in association with “7”.

Further, as the third pattern of the third-stage dictionary pattern, the divided dictionary pattern c3 is stored in association with the category "0".

As the first pattern of the fourth-stage dictionary pattern of the divided dictionary pattern memory 14, the divided dictionary pattern d is used.
1 is category “1”, “3”, “4”, “5”,
It is stored in association with "7" and "9".

As the second pattern of the fourth-stage dictionary pattern, the divided dictionary pattern d2 is category "6",
It is stored in association with “8” and “0”.

Further, as the third pattern of the fourth-stage dictionary pattern, the divided dictionary pattern d3 is stored in association with the category "2".

As the first pattern of the fifth-stage dictionary pattern of the divided dictionary pattern memory 14, the divided dictionary pattern e is used.
1 is category “2”, “3”, “5”, “6”,
It is stored in association with “8” and “0”.

As the second pattern of the fifth-stage dictionary pattern, the divided dictionary pattern e2 is the category "1",
It is stored in association with "4", "7", and "9".

The operation of the embodiment of the present invention will be described with reference to FIGS. Hereinafter, a case where the character cutout circuit 3 cuts out the print character "8" will be described.

When the typed character “8” is cut out by the character cutout circuit 3, the character pattern of the single typed character “8” is stored in the character pattern memory 11 of the character determination circuit 1. The character pattern dividing unit 12 divides the character pattern of the print character “8” stored in the character pattern memory 11 into preset vertical five stages, and the first to fifth divided character patterns a to e, respectively. Is stored in the divided character pattern memory 13.

When the first to the fifth divided character patterns a to e are stored in the divided character pattern memory 13, the matching section 15 divides the divided dictionary patterns a1 to a4 which are the first-stage dictionary patterns. Sequential reading is performed from the dictionary pattern memory 14 and the matching process (matching) is performed on the first-stage divided character pattern a, and the determination result candidate in the first stage is selected by the divided dictionary pattern that satisfies the specified threshold.

In this case, since the divided dictionary pattern a1 is a divided dictionary pattern satisfying the specified threshold value, the categories "0", "2",
“3”, “5”, “7”, “8”, “9” are selected.

Next, the matching section 15 sequentially reads the divided dictionary patterns b1 to b3 which are the second-stage dictionary patterns from the divided dictionary pattern memory 14 and performs the collation process on the second-stage divided character pattern b, Selection result candidates in the second row are selected according to the divided dictionary pattern that satisfies the specified threshold.

In this case, since the divided dictionary pattern b2 is a divided dictionary pattern satisfying the specified threshold value, the categories "0", "2", "that are the first stage determination result candidates as the second stage determination result candidates. 3 ”,“ 5 ”,“ 7 ”,
Categories “0”, “8”, and “9” including the divided dictionary pattern b2 are selected from “8” and “9”.

Further, the matching unit 15 sequentially reads the divided dictionary patterns c1 to c3 which are the dictionary patterns for the third stage from the divided dictionary pattern memory 14 and performs the collating process on the divided character pattern c of the third stage to define. The determination result candidates in the third row are selected according to the divided dictionary pattern that satisfies the threshold value.

In this case, since the divided dictionary pattern c1 is a divided dictionary pattern satisfying the specified threshold value, the categories "0", "8", "which are the second stage determination result candidates as the third stage determination result candidates. Categories “8” and “9” including the divided dictionary pattern c1 are selected from “9”.

Further, the matching unit 15 sequentially reads the divided dictionary patterns d1 to d3 which are the dictionary patterns for the fourth row from the divided dictionary pattern memory 14 and performs the collation process on the divided character pattern d of the fourth row to define the divided character patterns d. The determination result candidate in the fourth row is selected according to the divided dictionary pattern that satisfies the threshold value.

In this case, since the divided dictionary pattern d2 is a divided dictionary pattern satisfying the specified threshold value, the judgment result candidates in the fourth row are among the judgment result candidates in the third row in categories "8" and "9". The category "8" including the divided dictionary pattern d2 is selected from.

Furthermore, the matching unit 15 sequentially reads the divided dictionary patterns e1 and e2, which are the dictionary patterns for the fifth row, from the divided dictionary pattern memory 14 and performs the matching process on the divided character pattern e on the fifth row. The determination result candidates in the fifth row are selected according to the divided dictionary pattern that satisfies the specified threshold.

In this case, since the divided dictionary pattern e1 is a divided dictionary pattern satisfying the specified threshold value, 4 including the divided dictionary pattern e1 as the judgment result candidate in the fifth stage.
The category “8”, which is the determination result candidate in the second row, is selected.

Therefore, the category "8" that remains only in the above processing is output from the determination result determining section 16 as the determination result, and the determination processing is terminated.

When there are two or more judgment result candidates even though the above-described processing is performed on the divided character patterns divided by the character pattern dividing unit 12, or there is no judgment result candidate at all. Unread.

In this way, the character pattern of the print characters cut out by the character cutting circuit 3 is divided into a preset number of divisions by the character pattern division unit 12, and each of the divided character patterns is stored in the division dictionary pattern memory 14. By performing a matching process with a divided dictionary pattern divided into a predetermined number of divisions in the matching unit 15, and determining the character pattern of the above-mentioned print character based on the determination result candidates of the respective divided character patterns obtained from the matching process, Since overlapping of similar portions between the collation dictionaries can be avoided, the collation dictionary data can be reduced, and the same character determination as before the collation dictionary data amount reduction can be performed.

Therefore, it is possible to eliminate the overlapping collation of similar portions between the collation dictionaries, and it is possible to reduce the difference in collation processing time of each character pattern regardless of the storage order in the dictionary memory.

[0062]

As described above, according to the present invention, the cut-out type character is divided into a preset number of divisions, and the division result and the division dictionary pattern preliminarily divided into the above-mentioned division number. The capacity of the dictionary memory can be reduced by performing superposition and extracting the candidate character for each divided part from the superposition result and judging the character pattern, regardless of the storage order in the dictionary memory. There is an effect that it is possible to reduce the difference in the matching processing time of each character pattern.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a system configuration of an embodiment of the present invention.

FIG. 3 is a diagram showing an example of character pattern division according to an embodiment of the present invention.

FIG. 4 is a diagram showing an example of division of a dictionary pattern according to an embodiment of the present invention.

FIG. 5 is a diagram showing an example of a character determination procedure according to an embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 1 character determination circuit 3 character cutout circuit 11 character pattern memory 12 character pattern division unit 13 divided character pattern memory 14 division dictionary pattern memory 15 matching unit 16 determination result determination unit

Claims (4)

[Claims] 1. An optical character reading device that cuts out a typed character read from character image data for each character and determines a character pattern of the cut out typed character, wherein the cut out typed character is preset. Dividing means for dividing into numbers,
Storage means for storing a division dictionary pattern divided in advance into the number of divisions, and means for superimposing an output of the division means and a division dictionary pattern corresponding to the divided portion,
It has a means for extracting a candidate character for each divided portion from the result of the superposition, and a determination means for determining a character pattern of the print character based on the extracted candidate character for each divided portion. Optical character reading device. 2. The optical character reader according to claim 1, wherein the storage means is configured to store the divided dictionary pattern and a candidate character including the divided dictionary pattern in association with each other. 3. The candidate character of the character pattern of the print character is a candidate character including all of the divided dictionary patterns in which a match is detected in the superposition among the candidate characters extracted for each divided portion. The optical character reader according to claim 1 or 2, wherein the optical character reader is configured to output as. 4. The optical character reader according to claim 1, further comprising a holding unit that holds each of the divided parts divided by the dividing unit.