JP7067018B2 - Recognition program, recognition method and recognition device - Google Patents

Description

The present invention relates to a recognition program, a recognition method and a recognition device.

In order to monitor various meters installed in remote areas, including meters for electricity, gas, and water, there is known a technique for recognizing the display related to the measured value of the meter by image processing.

For example, as an example of a technique for recognizing a display of a drum type meter, a current character instrument recognition processing device has been proposed. As an explanation of this current character instrument recognition processing device, "a collation model image (corresponding to an expanded number car pattern) in which numbers from 0 to 9 are arranged vertically is prepared in advance and registered as a collation model image. Then, compare and search which position of the number car the acquired display value best matches, and calculate the displayed value in decimal units from the detected position information. " There is a description.

Japanese Patent Application Laid-Open No. 2003-242444 Japanese Unexamined Patent Publication No. 9-44601

However, with the above technique, the robustness of meter recognition may decrease.

That is, the interval at which the numbers are arranged on the drum on which the drum type meter is mounted may differ depending on the type of meter, or may differ depending on the manufacturer of the same type of meter. Nevertheless, in the above-mentioned current character instrument recognition processing device, in order to calculate the numerical value in decimal units from the number displayed on the drum of the last digit of the drum type meter, the numbers 0 to 9 are arranged vertically for collation. The model image is used uniformly. Therefore, if the number-to-number spacing in the matching model image does not match the number-to-number spacing in the drum, the numbers in the matching model image and the numbers in the drum will be misaligned and will be displayed on the drum. Numbers may be misrecognized. In this way, in the above-mentioned current character instrument recognition processing device, the constraint that the number-to-number spacing in the matching model image and the number-to-number spacing in the drum match is imposed, so that the robustness of character recognition is imposed. Decreases.

In one aspect, it is an object of the present invention to provide a recognition program, recognition method and recognition device capable of improving the robustness of meter recognition.

In one aspect, when the recognition program identifies a plurality of line drawing areas in the line drawing area of characters in the image, the recognition program identifies each character candidate from each line drawing area, and among the specified plurality of character candidates. , Specify each character that satisfies the condition of the character combination when the line drawing area is separated, and let the computer execute the process.

The robustness of meter recognition can be improved.

FIG. 1 is a diagram showing a configuration example of the meter monitoring system according to the first embodiment. FIG. 2 is a block diagram showing an example of the functional configuration of the server device according to the first embodiment. FIG. 3 is a diagram showing an example of a schematic diagram from cutting out the meter display area to dividing into the number display area. FIG. 4 is a diagram showing an example of a method for separating a plurality of character piece candidates. FIG. 5 is a diagram showing an example of a method of cutting out a partial template image. FIG. 6 is a diagram showing an example of a method of cutting out a partial template image. FIG. 7A is a diagram showing an example of the positional relationship between the blank portion and the numerical display area of the final digit. FIG. 7B is a diagram showing an example of the positional relationship between the blank portion and the numerical display area of the final digit. FIG. 7C is a diagram showing an example of the positional relationship between the blank portion and the numerical display area of the final digit. FIG. 8 is a flowchart showing a procedure for monitoring the meter measurement value according to the first embodiment. FIG. 9 is a flowchart showing the procedure of the recognition process according to the first embodiment. FIG. 10 is a diagram showing a hardware configuration example of a computer that executes the recognition program according to the first and second embodiments.

The recognition program, recognition method and recognition device according to the present application will be described below with reference to the accompanying drawings. It should be noted that this embodiment does not limit the disclosed technique. Then, each embodiment can be appropriately combined as long as the processing contents do not contradict each other.

[System configuration]
FIG. 1 is a diagram showing a configuration example of the meter monitoring system according to the first embodiment. The meter monitoring system 1 shown in FIG. 1 provides a meter monitoring service to the client terminal 30 by recognizing characters displayed on the drum type meters 2A to 2C installed in a remote location or the like by image processing. ..

As shown in FIG. 1, the meter monitoring system 1 includes a server device 10, cameras 20A to 20C, and a client terminal 30. In the following, when the drum type meters 2A to 2C are collectively referred to as "drum type meter 2", and when the cameras 20A to 20C are collectively referred to, the term "camera 20" may be used. Although FIG. 1 illustrates one server device 10 and one client terminal 30, one server device 30 may accommodate a plurality of client terminals 30. Further, although three cameras 20 are illustrated in FIG. 1, the number of cameras 20 accommodated in the server device 10 is not limited to three, and may be singular or plural.

The server device 10, the camera 20, and the client terminal 30 are connected via an arbitrary network NW. This network NW can be constructed by any kind of communication network such as the Internet, LAN (Local Area Network) and VPN (Virtual Private Network) regardless of whether it is wired or wireless.

The drum type meter 2 is a meter that displays measured values by rotating a drum having a plurality of digits.

Here, as an example of a line drawing on the drum mounted on the drum type meter 2, the following description will be given by giving an example in which numbers are arranged. In the following, measured values such as physical quantities and indicators measured by the meter may be referred to as "meter measured values". Further, the area where the number string corresponding to the meter measurement value is displayed may be described as "meter display area". Further, the area of numbers for one character displayed in each digit of the meter display area may be referred to as a "number display area". In the following, the number of digits starts counting from the leftmost digit to the rightmost digit in ascending order, the leftmost digit is described as the "starting digit", and the rightmost digit is referred to as the "last digit". May be described as.

When the meter measurement value of the drum type meter 2 is image-recognized, the following common items (1) to (7) are utilized.

(1) As an example, numbers from 0 to 9 are arranged in order from the top on the circumferential portion of the drum.
(2) The drum rotates in the direction from the front side to the back side of the meter display area, that is, from the vertical lower side to the upper side.
(3) The drum of the last digit rotates in conjunction with the fluctuation of the decimal point level of the meter measurement value.
(4) The drum of a digit other than the last digit rotates until the digit incremented by one in accordance with the timing at which the digit of the next lower digit moves from "9" to "0" becomes a fixed position.
(5) The number display area is larger than the size of a number for one character arranged on the drum.
(6) Two numbers may appear in the number display area at the same time, but they do not completely fit in the number display area.
(7) A blank portion is inserted as a delimiter between the numbers arranged on the drum.

The server device 10 is a computer that provides the above-mentioned meter monitoring service to the client terminal 30.

The label "server device" referred to here is only a classification from one aspect of the function, and the type of computer and its hardware configuration are not limited to a specific one. For example, the server device 10 can be implemented as package software or online software by installing a meter monitoring program that realizes the above meter monitoring service on a desired computer. For example, the server device 10 may be implemented as a Web server that provides the meter monitoring service, or may be implemented as a cloud that provides the meter monitoring service by outsourcing.

The camera 20 is an image pickup device equipped with an image pickup device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor).

For example, the camera 20 is attached to a drum type meter 2 having a one-to-one correspondence. At this time, the camera 20 is arranged so that at least the meter display area of the drum type meter 2 is included in the imaging range of the camera 20. Under such an arrangement of the camera 20, the camera 20 captures the meter display area of the drum meter 2 according to a request from the server device 10 or a setting instructed by an external device such as the server device 10, for example, a timer. .. In the following, an image in which the meter display area of the drum type meter 2 is captured may be referred to as a “meter image”. This meter image is uploaded to the server device 10 together with the identification information of the drum type meter 2 so that the individual such as the drum type meters 2A to 2C can be identified. At this time, the camera 20 may upload the meter image in real time, or may upload the meter image accumulated over a predetermined period by batch processing. Although the case where the drum type meter 2 and the camera 20 are arranged side by side is illustrated here, the drum type meter 2 and the camera 20 may not necessarily be arranged side by side on a one-to-one basis. For example, if one camera 20 can shoot a plurality of drum-type meters 2, one camera 20 may be provided for each of the plurality of drum-type meters 2.

The client terminal 30 is a computer that receives the above-mentioned meter monitoring service.

The label "client terminal" here is also a classification from one aspect of the function, and the type of computer and its hardware configuration are not limited to a specific one. For example, the client terminal 30 corresponds to a desktop computer such as a personal computer or a workstation. Not limited to such a desktop computer, a rack-top computer, a mobile terminal device, a wearable terminal, or the like may be adopted as a client terminal.

For example, when the client terminal 30 succeeds in login authentication to the server device 10 through an account authorized to use the meter monitoring service, the client terminal 30 displays the meter count value of the drum type meter 2 according to the instruction from the server device 10. It is possible to display a meter monitoring screen or the like. In addition, the client terminal 30 can also receive meter measurement values and the like as push notifications from the server device 10 at a predetermined periodic date and time.

[Functional configuration of server device 10]
FIG. 2 is a block diagram showing an example of the functional configuration of the server device 10 according to the first embodiment. As shown in FIG. 2, the server device 10 has a communication I / F (InterFace) unit 11, a storage unit 13, and a control unit 15. In FIG. 2, a solid line showing the relationship between data transfer is shown, but for convenience of explanation, only the minimum part is shown. That is, the input / output of data relating to each processing unit is not limited to the illustrated example, and the input / output of data other than those shown in the illustration, for example, between the processing unit and the processing unit, between the processing unit and the data, and between the processing unit and the outside. Data may be input and output between the devices.

The communication I / F unit 11 is an interface for controlling communication with another device, for example, a camera 20 or a client terminal 30.

As one embodiment, a network interface card such as a LAN (Local Area Network) card can be adopted for the communication I / F unit 11. For example, the communication I / F unit 11 can receive an image from the camera 20 and transmit various settings related to the camera 20, such as a date and time instructing the camera 20 to take an image, to the camera 20. Further, the communication I / F unit 11 accepts account information used for login authentication from the client terminal 30, and transmits a meter monitoring screen to the client terminal 30 that has succeeded in login authentication.

The storage unit 13 is a storage device that stores data used in various programs such as an OS (Operating System) executed by the control unit 15 and an application program that realizes the meter monitoring service.

As one embodiment, the storage unit 13 can be implemented as an auxiliary storage device in the server device 10. For example, an HDD (Hard Disk Drive), an optical disk, an SSD (Solid State Drive), or the like can be adopted as the storage unit 13. The storage unit 13 does not necessarily have to be mounted as an auxiliary storage device, and may be mounted as a main storage device in the server device 10. In this case, various semiconductor memory elements such as RAM (Random Access Memory) and flash memory can be adopted for the storage unit 13.

The storage unit 13 stores the template data 13a and the meter measurement value data 13b as an example of the data used in the program executed by the control unit 15. In addition to these data, other electronic data may be stored in the storage unit 13. For example, the storage unit 13 can also store account information and the like given to the user who uses the client terminal 30. The explanation of the template data 13a and the meter measurement value data 13b will be given together with the explanation of the control unit 15 in which each data is registered or referred to.

The control unit 15 is a processing unit that controls the entire server device 10.

As one embodiment, the control unit 15 can be implemented by a hardware processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). Here, a CPU and an MPU are exemplified as an example of a processor, but it can be implemented by any processor, for example, a GPGPU (Graphics Processing Unit) or a DSP (Digital Signal Processor), regardless of whether it is a general-purpose type or a specialized type. .. In addition, the control unit 15 may be realized by hard-wired logic such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The control unit 15 deploys the above meter monitoring program on a work area of a RAM such as a DRAM (Dynamic Random Access Memory) or a SRAM (Static Random Access Memory) mounted as a main storage device (not shown) to be described below. The processing part of is virtually realized.

As shown in FIG. 2, the control unit 15 includes an acquisition unit 15a, a cutting unit 15b, a recognition unit 15c, a separation unit 15d, a first specific unit 15e, a second specific unit 15f, and an assembly unit. It has 15 g and.

The acquisition unit 15a is a processing unit for acquiring an image.

As one embodiment, the acquisition unit 15a can acquire the meter image by uploading the meter image from the camera 20 to the server device 10. For example, the acquisition unit 15a can upload the meter image in real time each time the meter image is captured by the camera 20. As another example, when the upload instruction operation is executed from the client terminal 30, the acquisition unit 15a can also upload the meter image stored in the camera 20 up to that point. As a further example, the acquisition unit 15a may have the meter image uploaded at regular intervals, for example, every hour, one day, one week, or one month, or at a regular date and time, for example, at 12:00 every day or on the 15th day of every month. It does not matter if you let the meter image be uploaded to. The meter image uploaded from the camera 20 in this way can also be stored in the storage unit 13. In this case, by embedding the identification information of the drum type meter 2 associated with the camera 20 in the file name of the meter image, the metadata of the meter image, or the like, the individual of the drum type meter 2 imaged by the camera 20 can be identified. The meter image can be stored in the storage unit 13 in such a state.

As another embodiment, the acquisition unit 15a can also acquire a meter image from a removable medium such as a memory card or a USB (Universal Serial Bus) memory that stores the meter image. As a further example, the acquisition unit 15a can also acquire a meter image by receiving it from an external device other than the camera 20 via the network NW. As described above, the route for the acquisition unit 15a to acquire the meter image may be an arbitrary route and is not limited to a specific route.

The cutting unit 15b is a processing unit that cuts out a meter display area from an image.

As one embodiment, the cutout unit 15b can cut out a region in which the cutout is preset as a meter display area from the meter image acquired by the acquisition unit 15a. As another example, the cutting unit 15b recognizes a marker arranged in the vicinity of the meter display area of the drum type meter 2 from the meter image acquired by the acquisition unit 15a. By calibrating the relative position between the marker and the meter display area in advance, the cutting unit 15b obtains the position of the meter display area from the position of the marker on the meter image and cuts out the meter display area. Can be done.

As another embodiment, the cutout unit 15b causes the client terminal 30 to display the meter image acquired by the acquisition unit 15a and displays the aim of the rectangular region cut out from the meter image. The meter display area can also be cut out by accepting the user operation of aligning the aim of the rectangular area with the meter display area via the client terminal 30. In addition, the cutting unit 15b can also cut out the meter display area based on the color information corresponding to the background of the numbers included in the meter display area.

After the meter display area is cut out from the meter image in this way, the cutout unit 15b divides the meter display area into a numerical display area of each digit. For example, the cutting unit 15b divides the meter display area cut out from the meter image into a number display area according to the division of each digit in which division is set in advance on the meter display area. As another example, the cutting unit 15b searches for a color corresponding to the background of the numbers included in the meter display area cut out from the meter image in the same direction as the direction of the digits in which the digits are aligned in the meter display area. By doing so, the gap between the numbers and the numbers is detected from the meter display area. Further, the cutout portion 15b may divide the meter display area into a plurality of number display areas by dividing the gap between the numbers in the direction orthogonal to the digit direction.

FIG. 3 is a diagram showing an example of a schematic diagram from cutting out the meter display area to dividing into the number display area. As shown in FIG. 3, when the meter image 300 is acquired by the acquisition unit 15a, the cutting unit 15b cuts out the meter display area 310 of the drum type meter 2 from the meter image 300. After the meter display area 310 is cut out from the meter image 300 in this way, the cutout unit 15b divides the meter display area 310 into the number display areas 310A to 310F of each digit. In this case, six number display areas can be obtained from the number display area 310A having the start digit "1" to the number display area 310F having the final digit "N = 6" in order.

The recognition unit 15c is a processing unit that recognizes characters corresponding to the number display area.

As one embodiment, the recognition unit 15c initializes the value n of the register held by the digit counter (not shown) to an initial value, for example, "1". Subsequently, the recognition unit 15c selects in order from the number display area of the start digit "1" in the number display area divided from the meter display area by the cutting unit 15b. After that, the recognition unit 15c refers to the template data 13a stored in the storage unit 13 until the number display area of the final digit "N" is selected, and performs the following image processing in the number display area of each digit. Recognize the number corresponding to the number display area by executing. As an example of this template data 13a, 10 types of template images such as a template image of each number, that is, a template image of the number "0", a template image of the number "1", ..., A template image of the number "9" are referred to. Will be done.

With reference to such template data 13a, the recognition unit 15c executes matching of the template image with the partially image of the previously selected number display area, that is, so-called template matching, for each number. Here, in the digits other than the last digit, the numbers are present at fixed positions except when the digits are carried up, as described in (4) above. That is, it can be assumed that the center of the line drawing formed by the numbers and the center of the number display area substantially coincide with each other. Therefore, template matching is executed in a state where the center of the template image and the center of the number display area are aligned with each other. By such template matching, the similarity between the template image and the digit display area is obtained for each digit. Then, the recognition unit 15c recognizes the number of the template image for which the highest degree of similarity with the number display area of each template image is calculated as the number corresponding to the number display area. Subsequently, the recognition unit 15c increments the value n of the register held by the digit counter by one. After that, the recognition unit 15c repeatedly recognizes the number corresponding to the number display area until the value n of the register held by the digit counter becomes the final digit N.

The separation unit 15d is a processing unit that separates a plurality of character piece candidates included in the number display area.

As one embodiment, the separation unit 15d starts processing when the value n of the register held by the digit counter reaches the final digit N. That is, as described in (3) above, the drum of the final digit rotates in conjunction with the fluctuation of the decimal point level of the meter measurement value. Therefore, as described in (6) above, the display frame forming the outer frame of the number display area may include a plurality of numbers. From this, the separation unit 15d detects a blank portion inserted between the numbers in order to detect the number and the number delimiter arranged on the drum according to the above item (7). .. At this time, if a plurality of blank areas are detected, it can be determined that there is a high possibility that only one number is included in the number display area of the last digit. In this case, the separation unit 15d causes the recognition unit 15c to perform the same template matching as the recognition unit 15c, so that the number corresponding to the number display area of the final digit is recognized.

On the other hand, if only one blank area is detected, it is found that there is a high possibility that the number display area of the last digit contains two numbers. In this case, the separation unit 15d separates the number display area of the final digit into two with the blank portion detected from the number display area of the final digit as a boundary. As described in (6) above, the two separated regions do not completely fit the two numbers, so each region contains a character piece of a number. For this reason, one of the two separated regions may be described as the "first character fragment area" and the other separation destination may be described as the "second character fragment region". The first character piece area is an example of the first line drawing area. Further, the second character piece area is an example of the second line drawing area.

FIG. 4 is a diagram showing an example of a method for separating a plurality of character piece candidates. FIG. 4 shows the number display area 310F of the last digit among the number display areas 310A to 310F included in the meter display area 310 shown in FIG. The background color is identified from the number display area 310F of the last digit shown in FIG. For example, the separation unit 15d can identify the background color as "black" and the number color as "white" from the difference in contrast between the number portion and the background portion and the difference in the number of pixels and the area between the number portion and the background portion. .. In this case, the separation unit 15d detects a rectangular blob corresponding to the background color "black" and dividing the number display area 310F in the digit direction, that is, in the left-right lateral direction as the blank area 400. Here, since the direction of the digits in which the number strings corresponding to the meter measurement values are lined up is the horizontal direction, the separation unit 15d separates the number display area 310F vertically with the blank portion 400 crossing the number display area 310F as a boundary. do. As a result, the first character piece area 410 separated on the upper side and the second character piece area 420 separated on the lower side are obtained.

The first specific unit 15e is a processing unit that specifies a character piece candidate included in the character piece area for each character piece area.

As one aspect, the first specific unit 15e identifies a character piece candidate included in the first character piece area. Here, while the first character piece region separated on the upper side is likely to include the lower part of the number, it is unlikely to include the upper part of the number. For this reason, the first specific unit 15e generates a partial template image in which the lower part of the number of the template image is cut out for each template image.

FIG. 5 is a diagram showing an example of a method of cutting out a partial template image. For example, in the case of the template image 500 of the number "0", a partial template image is obtained by cutting out an area having a height of H1 corresponding to the first character piece area 410 upward from the position of the lowermost end of the number "0". 500A is generated. Further, in the case of the template image 510 of the number "1", a partial template image is obtained by cutting out an area having a height of H1 corresponding to the first character piece area 410 upward from the position of the lowermost end of the number "1". 510A is generated. In the same manner as this, the partial template image 520A to the partial template image 590A are generated from the template image 520 of the number "2" to the template image 590 of the number "9".

After the partial template image is generated in this way, the first specific unit 15e performs template matching between the partial template image and the partial image corresponding to the first character piece area for each partial template image. Run. In this template matching, the lower end of the partial template image and the lower end of the partial image corresponding to the first character piece area are aligned, and then the similarity between the two is calculated. For example, in the case of the number "0", template matching is executed by aligning the lower end of the partial template image 500A with the lower end of the first character piece area 410. For other numbers, the same template matching is performed even though the contents of the partial template image are different. As a result, the similarity between the partial template image and the number display area is obtained for each number.

On that basis, the first specific unit 15e uses the number of the partial template image for which the similarity with the first character piece region of each partial template image is calculated to be equal to or higher than a predetermined threshold value as the first character. Specify as a character piece candidate included in one area.

As another aspect, the first specific unit 15e identifies a character piece candidate included in the second character piece area. Here, while the second character piece region separated on the lower side is likely to include the upper part of the number, it is unlikely to include the lower part of the number. For this reason, the first specific unit 15e generates a partial template image in which the upper part of the number of the template image is cut out for each template image.

FIG. 6 is a diagram showing an example of a method of cutting out a partial template image. For example, in the case of the template image 600 of the number "0", a partial template image is obtained by cutting out an area having a height of H2 corresponding to the second character piece area 420 downward from the position of the uppermost end of the number "0". 600A is generated. Further, in the case of the template image 610 of the number "1", a partial template image is obtained by cutting out an area having a height of H2 corresponding to the second character piece area 420 downward from the position of the uppermost end of the number "1". 610A is generated. In the same manner as this, the partial template image 620A to the partial template image 690A are generated from the template image 620 of the number "2" to the template image 690 of the number "9".

After the partial template image is generated in this way, the first specific unit 15e performs template matching between the partial template image and the partial image corresponding to the second character piece area for each partial template image. Run. In this template matching, the upper end of the partial template image and the upper end of the partial image corresponding to the second character piece area are aligned, and then the similarity between the two is calculated. For example, in the case of the number "0", template matching is executed by aligning the upper end of the partial template image 600A with the upper end of the second character piece area 420. For other numbers, the same template matching is performed even though the contents of the partial template image are different. As a result, the similarity between the partial template image and the number display area is obtained for each number.

On top of that, the first specific unit 15e uses the numbers of the partial template image for which the similarity with the second character piece region of each partial template image is calculated to be equal to or higher than a predetermined threshold value as the second character. Specify as a character piece candidate included in one area.

The second specifying unit 15f specifies a combination that matches the numerical arrangement condition of the drum type meter 2 from the combinations of the character piece candidates in the first character piece area and the character piece candidates in the second character piece area. It is a processing unit.

As one embodiment, the second specific unit 15f selects one character piece candidate from the character piece candidates in the first character piece area. In the following, in order to distinguish the character piece candidate selected among the character piece candidates in the first character piece area from other character piece candidates, it may be described as "selected character piece candidate". Then, the second specific unit 15f is a character in the second character piece area that satisfies the above-mentioned number arrangement condition with the selected character piece candidate in the character piece candidate in the second character piece area. Determine if one candidate exists. That is, as described in (1) above, numbers from 0 to 9 are arranged in order from the top on the circumferential portion of the drum. According to this arrangement condition, it is determined whether or not there is a character piece candidate having a serial number following the number of the selected character piece candidate among the character piece candidates in the second character piece area. After that, the second specific unit 15f repeatedly selects from the character piece candidates in the first character piece area until the character piece candidate in the second character piece area satisfying the above-mentioned arrangement of numbers is found. A character piece candidate in the second character piece area that satisfies the above-mentioned number arrangement condition is searched for. By executing such a search, a combination of a character piece candidate in the first character piece area and a character piece candidate in the second character piece area that matches the numerical arrangement condition of the drum type meter 2 is identified. To.

This search will be specifically described with an example. Here, it is assumed that the search is executed under the conditions (a) and (b) shown below. (B) It is assumed that the character piece candidates in the first character piece area are "3", "5", and "9". (B) It is assumed that the character piece candidate in the second character piece area is "6". Under this condition, first, the number "3" is selected from the character piece candidates in the first character piece area. Then, it is determined whether or not a character having a serial number "4" following the number "3" of the selected character piece candidate exists in the character piece candidate in the second character piece area. Under this condition, the number "4" does not exist in the character piece candidates in the second character piece area. Therefore, the number "5" is selected again from the character piece candidates in the first character piece area. Then, it is determined whether or not a character having a serial number "6" following the number "5" of the selected character piece candidate exists in the character piece candidate in the second character piece area. In this case, as in the condition (b), the number "6" exists in the character piece candidate in the second character piece area. Therefore, the combination of the number "5" of the character piece candidate in the first character piece area and the number "6" of the character piece candidate in the second character piece area is a combination that meets the arrangement condition of the numbers of the drum type meter 2. Be identified.

That is, as assumed as the condition (a), even if template matching is performed with the partial template image only in the lower part of the number included in the first character piece area 410, the first character piece It is difficult to narrow down the character fragment candidates in the area to only the correct number "5". Therefore, there is a possibility that the number "3" and the number "9", which are similar in shape to the correct number "5" and the shape of the lower portion, are also included in the character piece candidates in the first character piece area. Even when there are a plurality of character piece candidates in the first character piece area in this way, by searching for a combination that matches the numerical arrangement conditions of the drum type meter 2, the character piece candidates in the first character piece area can be found. A combination of the number "5" and the number "6" of the character piece candidate in the second character piece area can be specified.

After the combination that matches the arrangement condition of the numbers of the drum type meter 2 is specified in this way, the second specific part 15f is the number of the integer part in the last digit from the combination and the fractional part in the last digit, for example, the decimal point. Further identify the number with the first decimal place.

Here, when the combination of the character piece candidate in the first character piece area and the character piece candidate in the second character piece area is found, since the last digit is in the middle of the carry, the integer part is a drum type. It can be determined that the number of the character piece candidate in the first character piece area that matches the arrangement condition of the number of the meter 2 is applicable.

Further, the second specific portion 15f can calculate the number of the decimal part from the position of the blank portion. For example, the second specific portion 15f calculates the displacement of the center position in the height direction of the blank portion with respect to the lowermost end of the numerical display area of the final digit. Then, the second specific portion 15f is the ratio of the displacement of the center position in the height direction of the blank portion to the height of the number display area of the final digit, for example, “displacement of the center position in the height direction of the blank portion ÷ final”. Calculate the "height of the digit display area" as a decimal part.

7A to 7C are diagrams showing an example of the positional relationship between the blank portion and the numerical display area of the final digit. 7A and 7C both show the positional relationship when the fractional part of the last digit is "0", but the number "5" is shown in the number display area 310F of the last digit shown in FIG. 7A. Is displayed in a fixed position, while the number "6" is displayed in a fixed position in the number display area 310F of the last digit shown in FIG. 7C. Further, FIG. 7B shows the positional relationship when the fractional part of the final digit is “0.5”. In the example of FIGS. 7A and 7C, when a plurality of blank parts are detected, the two numbers do not appear in the number display area 310F of the last digit, so that the calculation of the decimal part is not executed, but the above ratio is calculated. A calculation example will be described from the viewpoint of explaining that it corresponds to a decimal part.

As shown in FIG. 7A, when the number "5" is located at a fixed position, the center position of the blank portion 400 in the height direction exists at the same position as the lowermost end of the number display area 310F of the last digit. In this case, the displacement of the center position of the blank portion 400 in the height direction is also zero, so that the fractional portion can be calculated as "0". Further, as shown in FIG. 7B, when the drum starts rotating from the fixed position of the number "5" and rotates halfway until it switches to the fixed position of the number "6", it is in the height direction of the blank portion 400. The center position exists at the same position as the center position in the height direction of the number display area 310F of the last digit. In this case, the displacement of the center position in the height direction of the blank portion 400 is D ₁ (= 0.5 h ₁ ), so that the decimal part is calculated as D ₁ ÷ h ₁ (0.5 h ₁ ÷ h ₁ ). Therefore, it can be calculated as "0.5". Further, as shown in FIG. 7C, when the drum is rotated to the fixed position of the number "6", the center position in the height direction of the blank portion 400 reaches the same position as the uppermost end of the number display area 310F of the last digit. .. In this case, the displacement of the center position in the height direction of the blank portion 400 is D ₂ (= h ₁ ), so that the fractional portion is calculated as D ₂ ÷ h ₁ (h ₁ ÷ h ₁ ). Can be calculated.

Here, an example of the grounds that the position of the blank part is advantageous for calculating the number of the decimal part is given. That is, the width of the blank portion may differ depending on the type of meter, or may differ depending on the manufacturer of the same type of meter. On the other hand, from the viewpoint of suppressing complicated structure and control of a drive mechanism such as an actuator, the angle at which the drum is rotated when switching the display of numbers is designed to be constant. Therefore, in the same drum, the heights of the numbers are the same, and the heights of the blanks are the same. Therefore, even if the type of meter is different or the manufacturer of the meter is different, the decimal number can be calculated by the same logic, so that the robustness can be improved.

Here, as an example, the example of calculating the number of the decimal part from the position of the blank part has been described, but for example, the center of the number in the height direction exists in the frame of the number display area 310F of the last digit. It is also possible to calculate the fractional part from the position. In this case, if the center in the height direction of the digit area estimated from the first character piece area is located at the center of the frame, the decimal part is calculated as "0". Further, when the center in the height direction of the digit area estimated from the first character piece area or the second character piece area is located at the uppermost end in the frame, the decimal part is calculated as "0.5". .. Further, when the center in the height direction of the number area character estimated from the second character piece area is located at the lowermost end of the frame, the decimal part is calculated as "0". In addition to this, a known method can be used to calculate the fractional part.

The assembly unit 15g is a processing unit for assembling meter measurement values.

As one embodiment, the assembly unit 15g includes a number in the number display area recognized by the recognition unit 15c in each digit other than the final digit, and a number and a decimal number in the integer part of the final digit specified by the second specific unit 15f. Assemble the meter measurements based on the numbers in the part. For example, when the meter measurement value is expressed in decimal, the assembly unit 15g can calculate the meter measurement value by substituting the numerical value of each digit into the following equation (1).

Start digit number x 10 ^N-1 + Start 2 digits + 1 digit number x 10 ^N-2 , ..., Last digit number x 10 ⁰ ... (1)

The meter measurement values assembled in this way can be output to the following output destinations. For example, the assembly unit 15g can output the meter measurement value to the client terminal 30. In this case, as an example, the assembly unit 15g can display the meter monitoring screen or the like displaying the meter measurement value of the drum type meter 2 or the time series data thereof on the client terminal 30. Further, the assembly unit 15g can output the meter measurement value to the storage unit 13. In this case, the assembly unit 15g stores the meter measurement value data 13b in which the meter measurement value is associated with the identification information of the drum type meter 2 in the storage unit 13. In addition, the assembly unit 15g can also output to an application program located at the back end, for example, an application program that analyzes and notifies meter measurement values. For example, when it is output to the notification program, the notification program may determine whether or not the meter measurement value is equal to or higher than a predetermined threshold value, and output the meter measurement value which is equal to or higher than the threshold value to the information processing terminal of the person concerned. can. Further, when output to the analysis program, the analysis program can also execute statistical analysis of the meter measurement value and create a chart, for example, a graph or the like regarding the meter measurement value.

[Processing flow]
Next, the flow of processing of the server device 10 according to this embodiment will be described. Here, (1) the monitoring process of the meter measurement value executed by the server device 10 will be described, and then (2) the authentication process executed as a subflow thereof will be described.

(1) Monitoring process of meter measured value FIG. 8 is a flowchart showing a procedure of monitoring process of meter measured value according to the first embodiment. As an example, this process is a process that is repeatedly executed every time a meter image is acquired from the camera 20.

As shown in FIG. 8, when the meter image is acquired by the acquisition unit 15a (step S101), the cutting unit 15b cuts out the meter display area of the drum type meter 2 from the meter image acquired in step S101 (step S102). ). Subsequently, the cutting unit 15b divides the meter display area into a numerical display area of each digit (step S103).

Then, the recognition unit 15c initializes the value n of the register held by the digit counter (not shown) to an initial value, for example, “1” (step S104). Subsequently, in step S103, a "recognition process" for recognizing numbers for the number display area is executed in order from the number display area of the start digit "1" in the number display area divided from the meter display area (step S105). ..

After that, the recognition unit 15c increments the digit counter by one (step S106). Then, the processes of the above step S105 and the above step S106 are executed until the number of digits n held in the digit number counter reaches the final digit N (step S107 No).

Then, when the number of digits n held in the number of digits counter reaches the final digit N (step S107Yes), the assembling unit 15g assembles the meter measurement value from the number of each digit recognized in step S105 (step S108). The meter measurement value is output to a predetermined output destination (step S109), and the process is terminated.

(2) Recognition process FIG. 9 is a flowchart showing the procedure of the recognition process according to the first embodiment. This process corresponds to the process of step S105 shown in FIG. As shown in FIG. 9, when the number of digits n held in the number of digits counter is not the final digit "N" (step S201No), the recognition unit 15c refers to the template data 13a stored in the storage unit 13 and refers to the template data 13a. By executing image processing such as template matching in the digit display area of the digit corresponding to the digit number n held in the digit counter, the number corresponding to the digit display area is recognized (step S202), and the process is completed. do.

Further, when the number of digits n held in the number of digits counter is the final digit "N" (step S201Yes), the separation unit 15d has the final digit in order to detect the number separated from the numbers arranged on the drum. A blank portion inserted between numbers is detected from the number display area of (step S203).

At this time, if a plurality of blank areas are detected (step S204 No.), it can be determined that there is a high possibility that only one number is included in the number display area of the final digit. In this case, the separation unit 15d causes the recognition unit 15c to perform the same template matching as the recognition unit 15c to recognize the number corresponding to the number display area of the final digit (step S202), and ends the process.

On the other hand, when only one blank portion is detected (step S204Yes), it is found that there is a high possibility that two numbers are included in the number display area of the last digit. In this case, the separation unit 15d separates the number display area of the last digit into the first character piece area and the second character piece area with the blank part detected from the number display area of the last digit as a boundary (step S205). ).

Subsequently, in the first specific portion 15e, a degree of similarity of a predetermined threshold Th or more is calculated with the first character piece region in the partial template image in which the lower part of the number of each template image is cut out. The number of the partial template image is specified as a character piece candidate included in the first character piece area (step S206).

Further, in the first specific portion 15e, the similarity of the partial template image in which the upper half of the numbers of each template image is cut out to the second character piece region is calculated to have a degree of similarity equal to or higher than a predetermined threshold Th. The numbers in the partial template image are specified as character piece candidates included in the second character piece area (step S207).

After that, the second specific unit 15f is a drum from the combination of the character piece candidate of the first character piece area specified in step S206 and the character piece candidate of the second character piece area specified in step S207. A combination that matches the arrangement condition of the numbers of the formula meter 2 is specified (step S208).

After that, the second specifying unit 15f further specifies the number of the integer part in the last digit and the decimal part in the last digit, for example, the number having the first decimal place from the combination (step S209 and step S210), and performs processing. finish.

[One aspect of the effect]
As described above, the server device 10 according to the present embodiment specifies a number candidate for each character piece when the final digit of the drum type meter 2 contains a plurality of character pieces, and the number candidate of each character piece. From the combinations, the combination that matches the arrangement condition of the numbers of the drum type meter 2 is specified. In this way, since the drum display of the last digit can be recognized from the consistency of the number candidate specified from one character piece and the number candidate specified from the other character piece, a blank inserted between the numbers. It is possible to suppress a decrease in recognition accuracy due to a difference in the spacing between the parts. Therefore, according to the server device 10 according to the present embodiment, the robustness of meter recognition can be improved.

Although the embodiments relating to the disclosed apparatus have been described so far, the present invention may be implemented in various different forms other than the above-described embodiments. Therefore, another embodiment included in the present invention will be described below.

[Characters other than numbers]
In the first embodiment described above, the case where the drum display of the drum type meter 2 is a number is illustrated, but even when the drum display is a character other than a number, the processes shown in FIGS. 8 and 9 can be executed. can. For example, even when the drum display of the drum type meter 2 includes hiragana, katakana, and alphabets, the meter display can be recognized by defining the arrangement condition of each character between the characters arranged on the drum.

[Applying standalone]
In the first embodiment, the case where the meter monitoring system 1 is constructed as a client-server system is illustrated, but the meter monitoring system 1 may not necessarily be constructed as a client-server system. For example, the processes shown in FIGS. 8 and 9 executed by the functional unit of the server device 10 are executed stand-alone by various information processing devices equipped with the camera 20, for example, a portable terminal, a smartphone, a tablet terminal, or a wearable terminal. It doesn't matter if it is done.

[Distributed and integrated]
Further, each component of each of the illustrated devices does not necessarily have to be physically configured as shown in the figure. That is, the specific form of distribution / integration of each device is not limited to the one shown in the figure, and all or part of them may be functionally or physically distributed / physically in any unit according to various loads and usage conditions. Can be integrated and configured. For example, the acquisition unit 15a, the cutting unit 15b, the recognition unit 15c, the separation unit 15d, the first specific unit 15e, the second specific unit 15f, or the assembly unit 15g are connected via a network as an external device of the server device 10. You may.
Further, another device has an acquisition unit 15a, a cutting unit 15b, a recognition unit 15c, a separation unit 15d, a first specific unit 15e, a second specific unit 15f, or an assembly unit 15g, respectively, and is connected to a network to cooperate. By doing so, the function of the server device 10 may be realized.

[Recognition program]
Further, the various processes described in the above embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. Therefore, in the following, an example of a computer that executes a recognition program having the same function as that of the above embodiment will be described with reference to FIG.

FIG. 10 is a diagram showing a hardware configuration example of a computer that executes the recognition program according to the first and second embodiments. As shown in FIG. 10, the computer 100 includes an operation unit 110a, a speaker 110b, a camera 110c, a display 120, and a communication unit 130. Further, the computer 100 has a CPU 150, a ROM 160, an HDD 170, and a RAM 180. Each of these 110 to 180 parts is connected via the bus 140.

As shown in FIG. 10, the HDD 170 includes the acquisition unit 15a, the cutting unit 15b, the recognition unit 15c, the separation unit 15d, the first specific unit 15e, the second specific unit 15f, and the assembly shown in the first embodiment. A recognition program 170a that exhibits the same function as the unit 15g is stored. This recognition program 170a is the same as each component of the acquisition unit 15a, the cutting unit 15b, the recognition unit 15c, the separation unit 15d, the first specific unit 15e, the second specific unit 15f, and the assembly unit 15g shown in FIG. , Can be integrated or separated. That is, not all the data shown in the first embodiment may be stored in the HDD 170, and the data used for processing may be stored in the HDD 170. For example, among the functions of the recognition program 170a, a library in which the function of recognizing the number corresponding to the number display area of each digit or the function of recognizing the number corresponding to the number display area of the last digit is excerpted and modularized is obtained. It may be referred to the meter monitoring program that realizes meter monitoring.

Under such an environment, the CPU 150 reads the recognition program 170a from the HDD 170 and deploys it to the RAM 180. As a result, the recognition program 170a functions as the recognition process 180a, as shown in FIG. The recognition process 180a expands various data read from the HDD 170 into an area allocated to the recognition process 180a in the storage area of the RAM 180, and executes various processes using the expanded various data. For example, as an example of the process executed by the recognition process 180a, the process shown in FIG. 2 is included. In the CPU 150, not all the processing units shown in the first embodiment need to operate, and it is sufficient that the processing units corresponding to the processes to be executed are virtually realized.

The recognition program 170a may not necessarily be stored in the HDD 170 or the ROM 160 from the beginning. For example, the recognition program 170a is stored in a "portable physical medium" such as an FD, a CD-ROM, a DVD disk, a magneto-optical disk, or an IC card inserted in the computer 100. Then, the computer 100 may acquire the recognition program 170a from these portable physical media and execute it. Further, the recognition program 170a is stored in another computer or server device connected to the computer 100 via a public line, the Internet, a LAN, a WAN, or the like, and the computer 100 acquires the recognition program 170a from these and executes it. You may try to do it.

The following additional notes will be further disclosed with respect to the embodiments including the above embodiments.

(Appendix 1) When a plurality of line drawing areas are specified in the line drawing area of characters in the image, candidates for each character are specified from each line drawing area.
Among the specified multiple character candidates, each character that satisfies the condition of the character combination when the line drawing area is separated is specified.
A recognition program characterized by having a computer perform processing.

(Supplementary note 2) The recognition program according to Supplementary note 1, wherein the condition for combining the characters is an arrangement condition for numbers arranged on the drum of the drum type meter.

(Appendix 3) An image in which the meter display area of the drum type meter is captured is acquired.
When a plurality of line drawing areas are specified in the number display area of the last digit among the digits included in the meter display area cut out from the image, the blank part detected from the number display area of the last digit is bounded. Further causes the computer to perform a process of separating the number display area of the last digit into a first line drawing area and a second line drawing area along the direction of the digit.
In the process of identifying the character candidate, the template image of each number arranged in the digit included in the meter display area is referred to, and the respective numbers from the first line drawing area and the second line drawing area are referred to. The recognition program according to Appendix 2, which is characterized by identifying a candidate.

(Appendix 4) In the separation process, the first line drawing region is separated on the first direction side in which the drum corresponding to the girder rotates, and the second direction side opposite to the first direction. The second line drawing area is separated into
In the process of specifying the character candidate, the number candidate is specified by collating the partial template image in which a part of the template image near the second direction is cut out with the first line drawing area, and the above. The recognition program according to Appendix 3, wherein a candidate for a numerical value is specified by collating a partial template image obtained by cutting out a part of the template image toward the first direction with the second line drawing area.

(Supplementary Note 5) The process of specifying the character is described in Appendix 3 or Appendix 4, wherein the integer part and the decimal part of the last digit are further specified from the combination of numbers satisfying the arrangement condition of the numbers. Recognition program.

(Supplementary Note 6) The recognition program according to Supplementary Note 5, wherein the process of specifying the character is to specify the decimal part based on the position of the blank part detected from the number display area of the last digit.

(Appendix 7) When a plurality of line drawing areas are specified in the line drawing area of characters in the image, candidates for each character are specified from each line drawing area.
Among the specified multiple character candidates, each character that satisfies the condition of the character combination when the line drawing area is separated is specified.
A recognition method characterized by a computer performing processing.

(Supplementary Note 8) The recognition method according to Supplementary note 7, wherein the condition for combining the characters is an arrangement condition for numbers arranged on the drum of the drum type meter.

(Appendix 9) An image in which the meter display area of the drum type meter is captured is acquired.
When a plurality of line drawing areas are specified in the number display area of the last digit among the digits included in the meter display area cut out from the image, the blank part detected from the number display area of the last digit is bounded. Further, the computer further executes a process of separating the number display area of the last digit into a first line drawing area and a second line drawing area along the direction of the digit.
In the process of identifying the character candidate, the template image of each number arranged in the digit included in the meter display area is referred to, and the respective numbers from the first line drawing area and the second line drawing area are referred to. The recognition method according to Appendix 8, wherein the candidate is specified.

(Appendix 10) In the separation process, the first line drawing region is separated on the first direction side in which the drum corresponding to the girder rotates, and the second direction side opposite to the first direction. The second line drawing area is separated into
In the process of specifying the character candidate, the number candidate is specified by collating the partial template image in which a part of the template image near the second direction is cut out with the first line drawing area, and the above. The recognition method according to Appendix 9, wherein a numerical candidate is specified by collating the partial template image in which a part of the template image near the first direction is cut out with the second line drawing area.

(Supplementary Note 11) The process of specifying the character is described in Appendix 9 or Appendix 10, wherein the integer part and the decimal part of the last digit are further specified from the combination of numbers satisfying the arrangement condition of the numbers. Recognition method.

(Supplementary Note 12) The recognition method according to Supplementary Note 11, wherein the process of specifying the character is to specify the decimal part based on the position of the blank part detected from the number display area of the last digit.

(Appendix 13) When a plurality of line drawing areas are specified in the line drawing area of characters in the image, a first specific part that specifies a candidate for each character from each line drawing area, and
A second specific part that specifies each character that satisfies the condition of the character combination when the line drawing area is separated from the specified plurality of character candidates, and
A recognition device characterized by having.

(Supplementary Note 14) The recognition device according to Supplementary Note 13, wherein the condition for the combination of characters is an arrangement condition for numbers arranged on a drum of the drum type meter.

(Appendix 15) An acquisition unit that acquires an image in which the meter display area of the drum type meter is captured, and
When a plurality of line drawing areas are specified in the number display area of the last digit among the digits included in the meter display area cut out from the image, the blank part detected from the number display area of the last digit is bounded. Further has a separating portion for separating the number display area of the last digit into a first line drawing area and a second line drawing area along the direction of the digit.
The first specific unit refers to a template image of each number arranged in a digit included in the meter display area, and selects a candidate for each number from the first line drawing area and the second line drawing area. The recognition device according to Appendix 14, characterized in that it is specified.

(Appendix 16) The separation unit separates the first line drawing region on the side in the first direction in which the drum corresponding to the girder rotates, and on the side in the second direction opposite to the first direction. The second line drawing area is separated and
The first specific portion identifies a numerical candidate by collating a partial template image obtained by cutting out a part of the template image toward the second direction with the first line drawing area, and the template image. The recognition device according to Appendix 15, wherein a numerical candidate is specified by collating the partial template image in which a part of the first direction is cut out with the second line drawing area.

(Supplementary Note 17) The second specific part according to Supplementary note 15 or Supplementary note 16, wherein the integer part and the decimal part of the last digit are further specified from the combination of numbers satisfying the arrangement condition of the numbers. Recognition device.

(Supplementary Note 18) The recognition device according to Supplementary Note 17, wherein the second specific portion identifies the decimal portion based on the position of a blank portion detected from the digit display area of the last digit.

1 Meter monitoring system 2A, 2B, 2C Drum type meter 10 Server device 11 Communication I / F unit 13 Storage unit 13a Template data 13b Meter measurement value data 15 Control unit 15a Acquisition unit 15b Cutout unit 15c Recognition unit 15d Separation unit 15e 1st Specific part 15f Second specific part 15g Assembly part 20A, 20B, 20C Camera 30 Client terminal

Claims (7)

The image that the meter display area of the drum type meter was captured is acquired, and
When there is one blank portion in the numerical display area of the first digit included in the meter display area cut out from the image and crosses the numerical display area in a predetermined direction, the blank portion is described. By dividing the number display area into two with a portion as a boundary, the number display area is separated into a first character piece area and a second character piece area.
With reference to each template image of the numbers arranged in the digits included in the meter display area, a candidate for each number is identified from the first character piece area and the second character piece area.
Among the combinations of the number candidates specified from the first character piece area and the number candidates specified from the second character piece area, the numbers satisfying the arrangement condition of the numbers arranged on the drum of the drum type meter. The number of the first digit is specified based on the combination of the candidates of the first digit, and the second digit following the first digit is specified based on the relative position of the blank portion with respect to the digit display area of the first digit. Identify the digit number,
A recognition program characterized by having a computer perform processing. The process of specifying the number is characterized in that the number of the second digit is specified based on the ratio of the displacement of the center position in the height direction of the blank portion to the height of the number display area. The recognition program according to claim 1. In the separation process, the first direction side of the number display area orthogonal to the predetermined direction and in which the drum corresponding to the first digit rotates is separated as the first character piece area. The second direction side opposite to the first direction is separated as the second character piece region.
The process of specifying the numerical candidate is a partial template image in which a region having a height corresponding to the first character piece region is cut out from the end portion of the template image near the second direction and the first. A partial template in which a numerical candidate is identified by collation with the character piece area of the above, and an area having a height corresponding to the second character piece area is cut out from the end of the template image near the first direction. The recognition program according to claim 1 or 2 , wherein a numerical candidate is identified by collating an image with the second character piece area . The first digit corresponds to the last digit among the digits included in the meter display area.
The second digit corresponds to a subsequent digit following the last digit among the digits not included in the meter display area.
The recognition program according to any one of claims 1 to 3, wherein the recognition program is characterized in that. The last digit corresponds to the ones digit and
The following digit corresponds to the first decimal place.
The recognition program according to claim 4. The image that the meter display area of the drum type meter was captured is acquired, and
When there is one blank portion in the numerical display area of the first digit included in the meter display area cut out from the image and crosses the numerical display area in a predetermined direction, the blank portion is described. By dividing the number display area into two with a portion as a boundary, the number display area is separated into a first character piece area and a second character piece area.
With reference to each template image of the numbers arranged in the digits included in the meter display area, a candidate for each number is identified from the first character piece area and the second character piece area.
Among the combinations of the number candidates specified from the first character piece area and the number candidates specified from the second character piece area, the numbers satisfying the arrangement condition of the numbers arranged on the drum of the drum type meter. The number of the first digit is specified based on the combination of the candidates of the first digit, and the second digit following the first digit is specified based on the relative position of the blank portion with respect to the digit display area of the first digit. Identify the digit number,
A recognition method characterized by a computer performing processing. An acquisition unit that acquires an image in which the meter display area of a drum-type meter is captured, and
When there is one blank portion in the numerical display area of the first digit included in the meter display area cut out from the image and crosses the numerical display area in a predetermined direction, the blank portion is described. A separation unit that separates the number display area into a first character piece area and a second character piece area by dividing the number display area into two with a unit as a boundary.
A first to identify a candidate for each number from the first character piece area and the second character piece area with reference to each template image of the numbers arranged in the digits included in the meter display area. With a specific part
Among the combinations of the number candidates specified from the first character piece area and the number candidates specified from the second character piece area, the numbers satisfying the arrangement condition of the numbers arranged on the drum of the drum type meter. The number of the first digit is specified based on the combination of the candidates of the first digit, and the second digit following the first digit is specified based on the relative position of the blank portion with respect to the digit display area of the first digit. The second specific part that specifies the digit number, and
A recognition device characterized by having.

Images