JP5115123B2 - Bar code reader and program - Google Patents

Description

  The present invention relates to a barcode reader and a program.

  Conventionally, a barcode reader such as an HT (Handy Terminal) having a barcode reading function for reading a one-dimensional barcode is known. For example, in a store such as a convenience store, a barcode attached to a product is read by a barcode reader at the time of accounting (sales registration) processing and inventory, and identification information of the product recorded on the barcode is acquired. .

The barcode reading apparatus includes a storage unit, a control unit, and a barcode image reading unit. Further, in the barcode reader, when the barcode image is read by the barcode image reading unit and the barcode image includes a portion where the barcode condition is not satisfied due to poor print quality of the barcode or contamination of the barcode, The barcode condition unsatisfied part is replaced with a barcode condition satisfied part of another barcode image, and barcode synthesis is performed so that the barcode can be read (for example, see Patent Document 1).
JP 2001-43300 A

  However, in the above conventional barcode synthesis method, it is impossible to determine whether or not the barcode condition is satisfied unless the type of barcode being read (Code 39 or the like) is known in advance. For this reason, there has been a problem that it is difficult to apply a conventional bar code composition method when reading a plurality of bar codes as in an actual operating situation.

  Further, in the conventional bar code composition method, a part of the bar code image is replaced with another bar code image, so that the bar code characteristics may change before and after the replaced part. For example, if a barcode image acquired at a short distance from the barcode image reading unit is replaced with a barcode image acquired at a long distance, the data size changes before and after the replacement, and the barcode image There was a possibility that it would become a problem when decoding.

  An object of the present invention is to improve barcode reading performance.

In order to solve the above-described problem, a barcode reader according to claim 1 is provided.
Reading means for reading a barcode image composed of bar data indicating the width of a plurality of bars of the barcode from the barcode;
Storage means for storing, as base data, a barcode image corresponding to the barcode and serving as a reference for comparing barcode data;
When the latest barcode image read by the reading means is decoded and the decoding fails, the stored base data bar data and the latest barcode image bar data match, Control means for synthesizing the bar data of the latest barcode image and decoding the synthesized barcode image.

The invention according to claim 2 is the barcode reader according to claim 1,
Said control means compares said latest barcode images before combining with said base data, if the latest bar code image before the synthesis are suitable as base data than the base data, stored in the storage means The updated base data is updated with the latest barcode image before the synthesis .

The invention according to claim 3 is the barcode reader according to claim 1 or 2,
The control means is a variable for each bar data in all bar data of the latest barcode image after the synthesis , and a variable for each bar data in all bar data of the base data. When the difference in the variables is within a predetermined allowable range, it is determined that the bar data match.

The invention according to claim 4 is the barcode reader according to any one of claims 1 to 3,
The base data is a barcode image having the smallest number of bar data.

The invention according to claim 5 is the barcode reader according to any one of claims 1 to 4,
The base data is a barcode image having the longest number of decoding digits.

The invention according to claim 6 is the barcode reader according to any one of claims 1 to 5,
When the bar data of the latest barcode image is smaller than the bar data of the base data, the control unit synthesizes the bar data of the latest barcode image.

The program of the invention described in claim 7 is:
Computer
Reading means for reading a barcode image composed of bar data indicating the width of a plurality of bars of the barcode from the barcode,
Storage means for storing a bar code image corresponding to the bar code as a reference for bar data comparison as base data;
When the latest barcode image read by the reading means is decoded and the decoding fails, the stored base data bar data and the latest barcode image bar data match, Control means for synthesizing the latest barcode image data and decoding the combined barcode image;
To function as.

  According to the present invention, the barcode reading performance can be improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the illustrated example.

  Embodiments according to the present invention will be described with reference to FIGS. First, the apparatus configuration of the present embodiment will be described with reference to FIG. In FIG. 1, the structure of the handy terminal 1 of this Embodiment is shown.

  A handy terminal 1 as a barcode reading apparatus according to the present embodiment is a portable terminal having a barcode reading function. As shown in FIG. 1, a handy terminal 1 includes a CPU (Central Processing Unit) 11, an input unit 12, a RAM (Random Access Memory) 13 as a storage means, a display unit 14, a storage unit 15, a communication unit 16, and a power supply unit. 17, a scanner unit 18 serving as a reading unit, and the like, and each unit is connected via a bus 19. The scanner unit 18 includes a laser scanning unit 181, a laser light receiving unit 182, and a bar counter extraction unit 183.

  The CPU 11 centrally controls each part of the handy terminal 1. The CPU 11 expands a program designated from the system program and various application programs stored in the storage unit 15 in the RAM 13 and executes various processes in cooperation with the program expanded in the RAM 13. The CPU 11 functions as a control unit in cooperation with the program.

  The CPU 11 decodes the latest data optically read by the scanner unit 18 in cooperation with a decoding program to be described later, and when the decoding fails, the barcode image with the smallest number of bars is used as the base data. The latest data is synthesized and decoded. When the decoding fails, the latest data is synthesized and decoded using the barcode image having the longest number of decoding digits as the base data. Here, for one barcode, the width (counter value) of all the bars (and spaces) acquired by one scanning of the laser beam in the scanner unit 18 is called a barcode image. The width of each bar (or space) is called bar data. The base data is a bar code image that corresponds to the bar code to be read and serves as a bar data comparison reference. The latest data is the latest barcode image read by the scanner unit 18.

  The input unit 12 includes a trigger key for inputting scan execution and a keypad having cursor keys, numeric keys, various function keys, and the like, and outputs an input signal of each key pressed by the operator to the CPU 11. .

  The RAM 13 is a volatile memory, has a work area for storing various programs to be executed, data related to these various programs, and the like, and temporarily stores information. The display unit 14 includes an LCD (Liquid Crystal Display), an ELD (ElectroLuminescent Display), and the like, and performs screen display according to a display signal from the CPU 11.

  The storage unit 15 includes a ROM (Read Only Memory) that stores various programs and various data in a readable manner. The storage unit 15 may further include a flash memory that stores various information in a readable and writable manner. The storage unit 15 stores a decoding program.

  The communication unit 16 communicates various information with an external device using a wireless or wired communication method. The power supply unit 17 supplies power to each unit of the handy terminal 1. For example, the power supply unit 17 turns off the power supply in accordance with an instruction from the CPU 11.

  The scanner unit 18 optically reads a barcode based on an instruction from the CPU 11 and acquires a barcode image (bar data). The laser scanning unit 181 includes a laser light emitting unit and a movable mirror unit. The laser scanning unit 181 emits a laser beam from the light emitting unit, reflects it to the mirror unit, and emits it. At that time, the mirror unit is driven to change the reflection angle of the laser beam so that the laser beam moves on the barcode. Scan.

  The laser light receiving unit 182 receives reflected light obtained by reflecting the laser beam emitted from the laser scanning unit 181 with a barcode, and converts the received optical signal into an electrical signal. The bar counter extraction unit 183 detects a black and white binary counter value of the barcode from the electrical signal acquired by the laser light receiving unit 182 using a predetermined threshold value, and determines each bar (black color) from the counter value. ), Bar data indicating the width of each space (white) is acquired, and all bar data obtained by one laser scanning is acquired as a barcode image. Hereinafter, a bar and a space are collectively expressed as “bar” unless otherwise specified.

  Next, specific examples of the barcode image and the bar data will be described with reference to FIG. FIG. 2A shows an example of the barcode B and the width of each bar. FIG. 2B shows an example of a barcode image and bar data.

  It is assumed that a one-dimensional barcode B as shown in FIG. 2A is read by the scanner unit 18 in the direction of the arrow from left to right. The width of each bar of the barcode B is assumed to be bar data C1 to C17 in order. At this time, as shown in FIG. 2B, a barcode image including the respective bar data C1 to C17 is obtained by one laser scanning.

  Next, the operation of the handy terminal 1 will be described with reference to FIGS. First, the concept of bar code image composition in the present embodiment will be described with reference to FIG. FIG. 3 shows an example of synthesis of the base data and the latest data (hereinafter, the barcode image acquired latest by the scanner unit 18 is referred to as the latest data).

  When reading barcodes, the original bar should be read as a divided bar due to noise at the time of barcode reading, barcode quality defects (friction), scratches on the barcode, dirt, etc. Can happen. Therefore, in the present embodiment, the base data is used to combine the divided bar data into one and combine it with the original width bar data. That is, the bar data in the latest data is combined (combined) so that the latest data has the same ratio (size) as the base data.

  When scanning one barcode, the laser scanning unit 181 performs laser scanning a plurality of times, and a barcode image is acquired for each scanning. Of the acquired barcode images, an optimum barcode image that is considered to contain a lot of accurate data is used as base data.

  In the present embodiment, a barcode image in which the number of bar data included in one barcode image is minimum (hereinafter referred to as minimum data) is used as one of base data. This is because the minimum data is considered to be optimal data with few bar divisions because the number of bar data is the minimum. Also, a barcode image having the longest number of digits decoded in one barcode image (hereinafter referred to as the longest data) is used as one of the base data. This is because the longest data is data that has been most advanced in decoding processing, and is considered to be optimal data with a large area where correct data is obtained.

  As shown in FIG. 3, the bar data of the base data and the latest data are compared in order from the left during barcode reading. For example, if the bar data of the latest data is smaller than the bar data of the base data for a certain bar, the following two bar data are combined (combined) with the bar data of the latest data, and the bar data of the base data Compared with The two pieces of bar data are a combination of white (space) and black (bar), and it is considered that the original bar data is divided by this combination. The above comparison is repeated until the bar data match.

  In the example of FIG. 3, the latest data is divided compared to the base data in the b1 and b2 portions. For this reason, the bar data of the b1 and b2 portions are combined to generate combined data (the combined barcode image). In the b3 portion, the base data is divided compared to the latest data. For this reason, the bar data of the b3 portion is not synthesized, and the next bar data is compared. The synthesized data obtained in this way becomes a candidate for new base data, and the base data is updated to a more appropriate one.

  Next, a decoding process executed in the handy terminal 1 will be described with reference to FIGS. FIG. 4 shows the flow of the decoding process. FIG. 5 shows a flow subsequent to the decoding process of FIG.

  In the handy terminal 1, when the barcode is read by the scanner unit 18, the barcode is scanned with laser light a plurality of times. In the scanner unit 18, each time a laser beam is scanned by the laser scanning unit 181 and a barcode image (all barcode data) is acquired by the laser receiving unit 182 and the bar counter extraction unit 183, a decoding process is executed. Is done. As described above, in the handy terminal 1, the scanner unit 18 scans the barcode with the laser beam once to acquire one barcode image as a trigger, and is read from the storage unit 15 and appropriately stored in the RAM 13. The decoding process is executed in cooperation with the CPU 11 and the decoding program developed in FIG. The barcode image acquired by the scanner unit 18 is stored in the RAM 13 as the latest data.

  As shown in FIGS. 4 and 5, first, the barcode image (latest data) before synthesis acquired by the scanner unit 18 is decoded (step S1). In step S1, the number of digits successfully decoded (number of decoded digits) is also acquired. Then, it is determined whether or not the decoding in step S1 has been completely successful up to the end of the latest data (step S2).

  If the decoding in step S1 is not completely successful (step S2; NO), it is determined whether or not the barcode image (minimum data) having the smallest number of barcode data in the barcode image is stored in the RAM 13. (Step S3). When there is the minimum data (step S3; YES), the latest data is synthesized using the minimum data stored in the RAM 13 as the base data (step S4).

  Then, the synthesized data synthesized in step S4 is decoded (step S5). In step S5, the number of decoded digits is also acquired. Then, it is determined whether or not the decoding in step S5 is completely successful (step S6).

  If the decoding in step S5 is not completely successful (step S6; NO), it is determined whether or not the barcode image (longest data) having the longest number of decoded digits in the barcode image is stored in the RAM 13. (Step S7). When there is no minimum data (step S3; NO), the process proceeds to step S7. When there is the longest data (step S7; YES), the latest data is synthesized using the longest data stored in the RAM 13 as the base data (step S8).

  Then, the synthesized data synthesized in step S8 is decoded (step S9). In step S9, the number of decoded digits is also acquired. Then, it is determined whether or not the decoding in step S9 is completely successful (step S10).

  If the decoding in step S9 is not completely successful (step S10; NO), decoding failure is set in the status of the latest data (step S11). When there is no longest data (step S7; NO), it transfers to step S11. When the decoding of step S1 is completely successful (step S2; YES), the decoding of step S5 is completely successful (step S6; YES), or the decoding of step S9 is completely successful (step S10; YES) ) Successful decoding is set in the status of the latest data (step S12). The decoding success setting may be performed by executing decoding a plurality of times (for example, three times) and setting the status to the decoding success when all the decodings are completely successful.

  Then, it is determined whether or not the number of bar data of the latest data before synthesis is smaller than the number of bar data of the minimum data stored in the RAM 13 (step S13). If the number of bar data of the latest data before synthesis is smaller than the minimum data (step S13; YES), the minimum data stored in the RAM 13 is updated to the latest data before synthesis and the base data is updated (step S14).

  Then, it is determined whether or not the number of decoded digits of the latest data after synthesis is longer than the number of decoded digits of the longest data stored in the RAM 13 (step S15). It is assumed that the latest data after synthesis and the number of decoded digits are obtained in step S1, S5 or S10. When the number of bar data of the latest data before the synthesis is not smaller than the minimum data (step S13; NO), the process proceeds to step S15. When the number of decoding digits of the latest data after synthesis is longer than the longest data (step S15; YES), the longest data stored in the RAM 13 is updated to the latest data and the base data is updated (step S16), and the decoding process ends. To do. When the number of decoding digits of the latest data after the synthesis is not longer than the longest data (step S15; NO), the decoding process ends.

  Next, the latest data composition process using the base data in steps S4 and S8 of the decoding process will be described with reference to FIGS. FIG. 6 shows a flow of the synthesis process in the decoding process. FIG. 7 shows a continuation flow of the synthesis process of FIG. FIG. 8 shows how the base data and the latest data are combined. In step S4, the minimum data is used as the base data, and in step S8, the longest data is used as the base data.

  As shown in FIG. 8, each bar data of the base data is represented by a variable N, and each bar data of the latest data is represented by a variable n. In the synthesis process of the present embodiment, the latest data is synthesized using the base data to obtain synthesized data.

  As shown in FIGS. 6 and 7, first, unread bar data N of base data is read from the RAM 13 in order from the left (step S21). Then, the unread bar data n of the latest data is read from the RAM 13 one by one from the left (step S22). Then, in steps S21 and S22, it is determined whether or not all bar data of the base data or the latest data has been read (whether there is no bar data to be read in the immediately preceding step S21 or S22) (step S23).

  When all the bar data of the base data or the latest data has been read (step S23; YES), the synthesis process ends. When all the bar data of the base data or the latest data has not been read (step S23; NO), the difference d1 = | n−N | between the bar data n and the bar data N is calculated (step S24). Then, it is determined whether or not the difference d1 is smaller than n / 10 (step S25).

  When the difference d1 is smaller than n / 10 (step S25; YES), it is considered that the bar data N matches the bar data n, the bar data n is inserted into the combined data (step S26), and the process proceeds to step S21. The

  When the difference d1 is n / 10 or more (step S25; NO), it is determined whether or not the bar data n is smaller than the bar data N (step S27). When the bar data n is smaller than the bar data N (step S27; YES), it is considered that the latest data has been divided, the matching process of the latest data to the base data is started, and the bar data n of the latest data is started. The next bar data (n + 1) and (n + 2) are read from the RAM 13, and the combined bar data na = n + (n + 1) + (n + 2) is calculated (step S28).

  Then, the difference d2 = | na−N | between the bar data na and the bar data N is calculated (step S29). Then, it is determined whether or not the difference d2 is smaller than na / 10 (step S30). When the difference d2 is smaller than na / 10 (step S30; YES), it is considered that the bar data na coincides with the bar data N, the bar data na is inserted into the synthesized data (step S31), and the process proceeds to step S21. The

  When the difference d2 is greater than or equal to na / 10 (step S30; NO), it is determined whether or not the difference d2 is smaller than the difference d1 (step S32). When the difference d2 is smaller than the difference d1 (step S32; YES), the difference of the bar data is reduced by the synthesis, and the value of the difference d2 is substituted for the difference d1 (step S33). Then, the value of the bar data na is substituted for the bar data n (step S34), and the process proceeds to step S28.

  When the difference d2 is greater than or equal to the difference d1 (step S32; NO), the difference between the bar data is expanded by the synthesis, and the bar data n is inserted into the synthesized data (step S35). Then, the reading position of the latest data of bar data n is returned to the left by two bar data (step S36), and the process proceeds to step S21.

  When the bar data n is equal to or greater than the bar data N (step S27; NO), it is considered that the base data has been divided, the base data comparison position movement process is started, and the base data bar data N The next bar data (N + 1), (N + 2) is read from the RAM 13, and the combined bar data Na = N + (N + 1) + (N + 2) is calculated (step S37).

  Then, the difference d2 = | n−Na | between the bar data n and the bar data Na is calculated (step S38). Then, it is determined whether or not the difference d2 is smaller than n / 10 (step S39). When the difference d2 is smaller than n / 10 (step S39; YES), it is considered that the bar data n matches the bar data Na, the bar data n is inserted into the synthesized data (step S40), and the process proceeds to step S21. The

  When the difference d2 is n / 10 or more (step S39; NO), it is determined whether or not the difference d2 is smaller than the difference d1 (step S41). When the difference d2 is smaller than the difference d1 (step S41; YES), the difference of the bar data is reduced by the synthesis, and the value of the difference d2 is substituted for the difference d1 (step S42). Then, the value of the bar data Na is substituted for the bar data N (step S43), and the process proceeds to step S37.

  When the difference d2 is greater than or equal to the difference d1 (step S41; NO), the difference between the bar data is enlarged by the synthesis, and the bar data n is inserted into the synthesized data (step S44). Then, the reading position of the bar data N of the base data is returned to the left by two bar data (step S45), and the process proceeds to step S21.

  Here, a specific example of the synthesis process will be described with reference to FIG. FIG. 9 shows an example of the base data and the latest data.

  As shown in FIG. 9, consider base data having bar data A1 to A10 and latest data having bar data a1 to a12. First, since (a1-A1) <a1 / 10, it is considered that the bar data a1 and the bar data A1 match, and the bar data a1 is inserted into the synthesized data.

  Since (A2-a2)> a2 / 10, the bar data a3 and a4 are combined with the bar data a2. Since (A2− (a2 + a3 + a4)) <(a2 + a3 + a4) / 10, it is considered that the bar data (a2 + a3 + a4) and the bar data A2 match, and the bar data (a1 + a2 + a3) is inserted into the combined data.

  Similarly, the bar data a5 to a8 are considered to coincide with the bar data A3 to A6, and the bar data a5 to a8 are inserted into the synthesized data. Since (a9-A7)> a9 / 10, the bar data A8 and A9 are combined with the bar data A7. Since (a9− (A7 + A8 + A9))> a9 / 10 and (a9−A7) <(a9− (A7 + A8 + A9)), it is considered that the bar data a9 and the bar data A7 match, and the bar data a9. Is inserted into the composite data. In this way, the bar data a1 to a12 of the latest data are synthesized using the bar data A1 to A10 of the base data.

  As described above, according to the present embodiment, the handy terminal 1 decodes the latest data read by the scanner unit 18 and, when the decoding fails, the bar data of the base data stored in the RAM 13 and the latest data. Two bar data (space and bar) following the bar data of the latest data are combined to generate combined data so that the bar data matches, and the combined data is decoded. For this reason, even when decoding fails due to noise, barcode printing quality defects, dirt, scratches, etc., the latest data can be appropriately synthesized and decoded based on the base data, and the barcode reading performance can be improved.

  Also, it is determined whether or not the number of bar data of the latest data before synthesis is larger than the number of bar data of the base data. If the number of bar data of the latest data before synthesis is large, the minimum data is the latest data before synthesis. Update. Also, it is determined whether the number of decoding digits of the latest data after synthesis is longer than the number of decoding digits of the base data. If the number of decoding digits of the latest data after synthesis is large, the longest data is replaced with the latest data after synthesis. Update. For this reason, the base data can be easily updated with the latest data before synthesis or after synthesis.

  Further, when the difference between the bar data of the latest data before or after synthesis and the bar data of the base data is smaller than 1/10 of the bar data of the latest data, it is determined that the bar data match. For this reason, it is possible to appropriately determine the coincidence between the bar data of the latest data and the bar data of the base data with the error of the bar data as an allowable range.

  As the base data, the minimum data that is a barcode image with the minimum number of bar data is used. For this reason, an appropriate barcode image can be used as the base data.

  As the base data, the longest data, which is a barcode image having the longest number of decoding digits, was used. For this reason, an appropriate barcode image can be used as the base data.

  In addition, when the bar data of the latest data is smaller than the bar data of the base data, the bar data of the latest data is synthesized into synthesized data. Therefore, synthesized data can be generated from the latest data as a decoding target.

  The description in the above embodiment is an example of the barcode reading apparatus and the program according to the present invention, and the present invention is not limited to this.

  In the above embodiment, the handy terminal is used as the bar code reader. However, other bar codes such as a bar code reader connected to an ECR (Electronic Cash Register), a POS (Point Of Sales System) terminal or the like are used. It may be a reading device.

  In the above embodiment, the barcode data having the smallest number of barcode data and the barcode image having the longest number of decoding digits are described as the base data. However, the present invention is not limited to this. . For example, as base data, a bar code image with a bar data ratio distribution within a certain range (bar thickness is a constant ratio), or all bar data with a certain value or more (bar width is too narrow) No) A bar code image or the like may be used.

  In the above embodiment, the minimum data as base data is updated with the latest data before synthesis, and the longest data as base data is updated with the latest data after synthesis. However, the present invention is not limited to this. It is not a thing. For example, the base data may be updated with at least one of the latest data before and after synthesis, such as a configuration in which the minimum data is updated with the latest data after synthesis and the longest data is updated with the latest data before synthesis. .

  In the above embodiment, when decoding of the latest data before synthesis fails, the latest data is synthesized and decoded using the minimum data, and when decoding of the latest data using the minimum data fails, Although it has been described as a configuration for synthesizing and decoding the latest data using the longest data, it is not limited to this. For example, the configuration may be such that the latest data is synthesized and decoded using one type of base data, or the latest data may be synthesized and decoded using a plurality of types of base data. Further, the order of base data to be combined and decoded is not limited to a specific order.

  Moreover, it is needless to say that the detailed configuration and detailed operation of each component of the handy terminal 1 in the above embodiment can be changed as appropriate without departing from the spirit of the present invention.

It is a block diagram which shows the structure of the handy terminal of embodiment which concerns on this invention. (A) is a figure showing an example of the width of a bar code and each bar. (B) is a figure which shows an example of a barcode image and bar data. It is a figure which shows an example of a synthesis | combination with base data and the newest barcode image. It is a flowchart which shows a decoding process. 5 is a flowchart showing a continuation of the decoding process of FIG. It is a flowchart which shows the synthetic | combination process in a decoding process. It is a flowchart which shows the continuation of the synthetic | combination process of FIG. It is a figure which shows the mode of a synthesis | combination with base data and the newest data. An example of base data and the latest data is shown.

Explanation of symbols

1 Handy terminal 11 CPU
12 Input unit 13 RAM
14 Display unit 15 Storage unit 16 Communication unit 17 Power supply unit 18 Scanner unit 181 Laser scanning unit 182 Laser light receiving unit 183 Bar counter extraction unit 19 Bus

Claims (7)

Reading means for reading a barcode image composed of bar data indicating the width of a plurality of bars of the barcode from the barcode;
Storage means for storing, as base data, a barcode image corresponding to the barcode and serving as a reference for comparing barcode data;
When the latest barcode image read by the reading means is decoded and the decoding fails, the stored base data bar data and the latest barcode image bar data match, Control means for synthesizing the latest barcode image and decoding the combined barcode image;
A barcode reader. Said control means compares said latest barcode images before combining with said base data, if the latest bar code image before the synthesis are suitable as base data than the base data, stored in the storage means The barcode reader according to claim 1, wherein the base data is updated with the latest barcode image before the synthesis . The control means is a variable for each bar data in all bar data of the latest barcode image after the synthesis , and a variable for each bar data in all bar data of the base data. The bar code reading device according to claim 1, wherein when the difference between the variables is within a predetermined allowable range, it is determined that the bar data matches.   4. The barcode reader according to claim 1, wherein the base data is a barcode image having a minimum number of barcode data. 5.   5. The barcode reader according to claim 1, wherein the base data is a barcode image having the longest number of decoding digits.   The said control means combines the bar data of the said latest barcode image, when the bar data of the said latest barcode image is smaller than the bar data of the said base data. The barcode reader according to the description. Computer
Reading means for reading a barcode image composed of bar data indicating the width of a plurality of bars of the barcode from the barcode,
Storage means for storing a bar code image corresponding to the bar code as a reference for bar data comparison as base data;
When the latest barcode image read by the reading means is decoded and the decoding fails, the stored base data bar data and the latest barcode image bar data match, Control means for synthesizing the latest barcode image data and decoding the combined barcode image;
Program to function as.

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