JPH10240868A - Device for reading character - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve recognition ratio in a character recognizing device for operating character recognition to a binarized slip image. SOLUTION: An image I1 of a binarized slip 1 is received by a facsimile equipment(FAX) 2, and stored in an image memory 3. A segmenting part 4 segments an area I2 of character units of the slip image. A filter part 10 is provided with five logical filters 11-15 for operating a filtering processing by different rules, and for example, the logical filter 11 is selected and used at first, and then the shaping of a character pattern in the area I2 is operated. A recognizing part 21 operates character recognition to the shaped character pattern. In this case, when the character recognition is impossible, the selection of the logical filters 11-15 is changed by the instruction of a recognition controlling part 22, and the shaping of the character pattern and the character recognition is operated by using the changed logical filter 12. Afterwards, the similar processing is repeated, and the plural number of times of character recognition is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character reading device represented by an optical character reading device (hereinafter referred to as "OCR").

[0002]

2. Description of the Related Art A conventional OCR takes an image of a form as a multi-valued image, and binarizes the density of the multi-valued image with a preset threshold value. Character recognition is performed on the binarized image obtained as a result of the binarization, the character written or printed on the form is recognized, and the character code is output. Conventionally, in order to improve the recognition rate of character recognition, when rejection (event in which the character code cannot be searched) occurs in the first character recognition, the threshold for binarization is changed to change the character in the binarized image. Perform character recognition multiple times by changing the pattern. Thereby, a high character recognition rate is obtained.

[0003]

However, the conventional OCR has the following problems. Recently, there has been an increasing demand for performing character recognition on a form image transmitted by facsimile communication, and an OCR having an input unit configured as a facsimile apparatus has been commercialized. However, the image data input to the OCR via the facsimile apparatus is not a multi-valued image but a binary image represented by a binary value. Therefore, character recognition is performed only once, and the recognition rate in character recognition cannot be improved.

[0004]

According to a first aspect of the present invention, there is provided a character recognition apparatus comprising: a receiving unit, an image memory, a cutout unit, a filter unit, A recognition unit and a recognition control unit are provided. The receiving means is for receiving the binarized form image. The image memory stores the form image. The cutout unit cuts out an area including a character pattern to be read from the form image stored in the image memory. The filter unit has a plurality of logical filters for resetting the value of each pixel in the area according to different rules according to the situation of peripheral pixels, and uses a designated logical filter among the plurality of logical filters. The character pattern in the area is shaped. The recognition section performs character recognition on the shaped character pattern and outputs a character code obtained by the character recognition. A recognition control unit configured to issue a new instruction to the filter unit when the character code is not obtained as a result of giving the instruction to the filter unit; And a function of changing the logical filter used in the filter unit and causing the filter unit and the recognition unit to execute the process a plurality of times.

According to a second aspect of the present invention, a character recognition device includes the following receiving means, an image memory, a cutout unit, a filter unit, a recognition unit, and a recognition control unit. The receiving means is
The binarized form image is received. The image memory stores the form image. The cutout unit cuts out an area including a character pattern to be read from the form image stored in the image memory. The filter unit has a plurality of logical filters that reset the value of each pixel in the region according to different rules according to the situation of peripheral pixels, and uses a designated logical filter among the plurality of logical filters. The character pattern in the area is shaped. The recognizing unit performs character recognition on the shaped character pattern, and outputs a character code obtained by the character recognition or information on the character pattern accompanying the character recognition. The recognition control unit has a function of giving the instruction to the filter unit, and when the character code is not obtained as a result of giving the instruction, a new function is provided to the filter unit in accordance with the information on the character pattern. A function of issuing an instruction and arbitrarily changing a logical filter used in the filter unit, and causing the filter unit and the recognition unit to execute the process a plurality of times.

According to the first and second aspects of the present invention, since the character recognition device is configured as described above, the form image stored in the image memory is a binary image represented by a binary image. By changing the logical filter of the part, the character pattern of the character to be recognized changes. If character recognition is performed on the changed character pattern, a character code can be easily extracted. Since the recognition control unit appropriately gives an instruction to the filter unit and changes the logical filter, character recognition can be performed a plurality of times. Therefore, the above problem can be solved.

[0007]

FIG. 1 is a block diagram showing the configuration of a character recognition apparatus according to an embodiment of the present invention. This character recognition device is for recognizing characters written or printed on a form 1, and is a facsimile device (FAX) as a receiving means.
2 is provided. The binarized image of the form 1 is sent to the facsimile apparatus 2 via a telephone line (not shown). On the output side of the facsimile machine 2, an image memory 3 for storing an image I1 of the form 1 via the facsimile machine 2 is connected. A cutout section 4 is connected to the output side of the image memory 3, and the cutout section 4
The filter unit 10 is connected to the output side of the. The pattern memory 20 is connected to the output side of the logic filter unit 10. The recognition unit 21 is connected to the output side of the pattern memory 20. The recognition unit 21 has two output destinations,
One of the output destinations is an output terminal OUT of the character recognition device.
It has become. The other output destination is the recognition control unit 22. The recognition control unit 22 is configured to give an instruction to the filter unit 10.

The extracting section 3 has a function of extracting an area I2 in units of one character, for example, from the image stored in the image memory 3. The filter unit 10 has, for example, five logical filters 11, 12, 13, 14, and 15. The input side of each of the logical filters 11 to 15 is connected to the output side of the extracting unit 4, and the output side of each of the logical filters 11 to 15 is connected to the input side of the pattern memory 20. These logical filters 11 to 15 reset the values of the pixels in the area I2 according to different rules. The filter unit 10 receives the logical filter 1 according to an instruction from the recognition control unit 22.
Any one of 1 to 15 is selected, and the data of the area output by the selected logical filter is provided to the pattern memory 20. FIG. 2 shows the first logical filters 11 to 11.
15 is a diagram for describing filtering processing by No. 15. FIG. FIG. 2 shows nine adjacent pixels X1 to X9. X5 of these is the target pixel, and pixels X1 to X
4, X6 to X9 are peripheral pixels. When performing the filtering process, the values of the pixels X1 to X9 are substituted into the following equation (1), and the result of the calculation of the equation (1) is compared with the value T to set the value of the target pixel X5. .

[0009]

(Equation 1) When the pixels X1 to X9 are white and their values are all “0”, the calculation result of the expression (1) becomes smaller than the value T, and the value of the target pixel X5 is also set to “0” white. Pixels X1 to X
9 is black and all the values are “1”, the calculation result of the expression (1) becomes larger than the value T, for example, and the target pixel X5
Is also set to "1" black. Such setting of the target pixel is performed by the logical filters 11 to 15 for all the pixels in the region I2. Here, the value T can be set arbitrarily.
, The filtering processing result is different. On the other hand, the value of the target pixel X5 is weighted (1)
The result of the filtering process differs depending on the calculation of the expression. FIGS. 3A and 3B are diagrams for explaining specific examples of the rules of the filtering process.
FIG. 3B is a diagram showing a change in the character pattern according to FIGS. 3A and 3B, respectively.

Each of the logical filters 11 to 15 performs a filtering process on the area I2 according to different rules given in advance as conditions. The rules include, for example, the weighting of the target pixel X5 in the equation (1) and the value T Is the set value. In FIG. 3A, the value T is set to 3, and the value of the target pixel X5 is set to “0” for white and “1” for black. In FIG. 3B, the value T is set to 5, and the value of the target pixel X5 is set to "0" for white and weighted to "3" for black. When the filtering process is performed using the rule of FIG. 3A, as shown in FIG.
Changes to the character pattern P2. When the filtering process is performed using the rule of FIG. 3B, the character pattern P1 changes to a character pattern P3 as shown in FIG. 4B. When the character pattern P2 and the character pattern P3 are compared, the noise N1 is removed for both, but the line widths of the characters are different. The pattern P2 has no cut and has a good line width,
Suitable for character recognition. Each of the logical filters 11 to 15 is
Conditioning is performed so that the combination of the weight of the target pixel and the value T is different, and noise removal and character pattern smoothing are performed by filtering processing with different rules.

Next, the operation of the character recognition device shown in FIG. 1 will be described. The facsimile device 2 is provided with a facsimile signal from a communication partner. By receiving the facsimile signal, the binarized image I1 of the form 1 is input, and the image I1 is stored in the image memory 3. The extracting unit 4 extracts an area I2 in units of one character from the image I1. The area I2 includes a character pattern to be recognized. The character recognition device shown in FIG.
Is performed for the first time (hereinafter, referred to as 1st scan). In the first scan, the filter unit 10 selects and activates the logical filter 11 according to an instruction from the recognition control unit 22. The logical filter 11 performs a filtering process based on a conditioned rule, and resets each pixel of the region I2 using Expression (1). Thus, the shaped character pattern is stored in the pattern memory 20. The recognizing unit 21 performs character recognition by comparing the character pattern stored in the pattern memory with the dictionary. When the character code corresponding to the character to be recognized is obtained by the character recognition of the first scan, the character code is output from the output terminal OUT. If the character code cannot be extracted because it cannot be recognized,
A reject signal is provided from the recognition unit 21 to the recognition control unit 22.

Recognition control unit 22 receiving a reject signal
Gives a new instruction to the filter unit 10 to execute the second character recognition processing (2nd scan). The filter unit 10 selects and activates the logical filter 12 according to the new instruction. The logical filter 12 performs a filtering process according to a conditioned rule, and resets each pixel of the region I2 using Expression (1). As a result, the shaped character pattern is stored in the pattern memory 20 as in the case of the first scan, and the recognition unit 21 performs character recognition by comparing the character pattern stored in the pattern memory with the dictionary. If the character code cannot be extracted by the second scan, the third to fifth recognition processes are performed while changing to the logical filters 13 to 15 as in the first scan and the second scan. As described above, in the present embodiment, the filter unit 10 is provided with the logical filters 11 to 15 that reset the values of the respective pixels in the area I2 according to different rules according to the situation of the peripheral pixels. Are not obtained, the logical filters 11 to
The character pattern is shaped by changing the selection of fifteen, and character recognition is performed a plurality of times. Therefore, even when the given image of the form 1 is binary, a character pattern suitable for character recognition can be obtained, and the character recognition rate can be improved.

Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, there are the following modifications. (1) The number of logic filters 11 to 15 is not limited to five and may be increased. (2) In the above embodiment, the logical filters 11 to 15 are sequentially selected. However, when character recognition is performed by the recognition unit 21, information such as the line width of a character pattern and a character obtained along with the character pattern are obtained. May be fed back to the recognition control unit 22, and an arbitrary logical filter may be selected according to the information. By doing so, the number of scans can be reduced, and the processing can be speeded up.

[0014]

As described above in detail, according to the first and second aspects of the present invention, there are provided a receiving means for receiving a binarized form image, an image memory, a cutout section and a recognition section. A character recognition device, a filter unit having a plurality of logical filters, a function of giving an instruction to the logical filter unit, and a function of changing a logical filter used in the filter unit when a character code is not obtained. Since the recognition control unit is provided, even if the image of the form is given in binary, character recognition can be performed a plurality of times, and the character recognition rate is improved.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating filtering processing by logical filters 11 to 15 in FIG. 1;

FIG. 3 is a diagram illustrating a specific example of a rule of a filtering process.

FIG. 4 is a diagram showing a change in a character pattern according to FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 form 2 facsimile device 3 image memory 4 cutout unit 10 filter unit 11 to 15 logical filter 20 pattern memory 21 recognition unit 22 recognition control unit

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masaru Uchizu Oki Electric Industry Co., Ltd., 1-7-12 Toranomon, Minato-ku, Tokyo

Claims (2)

[Claims] A receiving unit that receives a binarized form image; an image memory that stores the form image; and an area including a character pattern to be read is cut out from the form image stored in the image memory. A cutout unit, comprising a plurality of logical filters for resetting the value of each pixel in the area according to different rules according to the situation of peripheral pixels, using a designated logical filter among the plurality of logical filters A filter unit for shaping a character pattern in the area, performing a character recognition on the shaped character pattern, and outputting a character code obtained by the character recognition; and And a logical instruction to be issued to the filter unit when the character code is not obtained as a result of the instruction. And a function of changing the filter, and a recognition control unit to perform multiple processes in the filter unit and the recognition unit, character reading apparatus characterized by comprising. 2. A receiving means for receiving a binarized form image, an image memory storing the form image, and cutting out an area including a character pattern to be read from the form image stored in the image memory. A cutout unit, comprising a plurality of logical filters for resetting the value of each pixel in the area according to different rules according to the situation of peripheral pixels, using a designated logical filter among the plurality of logical filters A filter unit for shaping a character pattern in the area by performing character recognition on the shaped character pattern, and information on the character code obtained by the character recognition or the character pattern obtained by the character recognition. And a function for giving the instruction to the filter unit, and when the character code is not obtained as a result of giving the instruction. A function of issuing a new instruction to the filter unit in accordance with the information on the character pattern and arbitrarily changing a logical filter used in the filter unit, and performing a process in the filter unit and the recognition unit a plurality of times. A character reading device, comprising: a control unit;