JP2009151504A - Code recognition device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a program for recognizing a bar code in an appropriate code system by discriminating which code system the bar code is written in when the whole of bar codes to be read can be decoded as multiple kinds of bar codes. <P>SOLUTION: This code recognition device 3 comprises a decoding part 31A consisting of an array of multiple kinds of graphic elements and decoding codes expressed on media in a plurality of code systems using predetermined kinds of graphic elements respectively; a decoding content storage processing part 31B storing processed content data indicating at least a part of contents of decoding during decoding on each code system; a likelihood computing part 31C computing likelihood of description in each code system according to the processed content data; and an output part 31D outputting the decoding result in one of the code systems according to the likelihood. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a code recognition device and a program, and more particularly to a decoding process using an appropriate code system.

  For example, when a barcode recognition apparatus has a plurality of types of barcodes such as a barcode of a postal matter, a barcode code system is required to perform processing by distinguishing the barcode code system. .

Patent Document 1 is an invention made in view of such a need, and discloses a method for appropriately recognizing a barcode even when a barcode of a different type is included in a part of a predetermined barcode. Has been. FIG. 1 is an example showing a barcode in such a case. Since the barcode to be read cannot be determined from the top and bottom, it is first decoded by various code systems from the left and right sides. The figure shows that the barcode can be decoded as CODE39 when decoding from the left side, and part of it as NW7 when decoding from the right side.
JP 2006-227796 A

  However, as shown in FIG. 2, the entire barcode that should be decoded by CODE 128 may approximate the theoretical value represented by NW7. In this case, whether the barcode (a) to be read indicates the theoretical value (b) of the barcode described in NW7 or the theoretical value (c) of the barcode described in CODE128. There is a possibility that the barcode cannot be recognized by the conventional technology and the barcode is recognized with an incorrect code system.

  The present invention has been made in view of the above problems, and the object thereof is a barcode described in any code system when the entire barcode to be read can be decoded as a plurality of types of barcodes. It is an object of the present invention to provide an apparatus and a program for recognizing a bar code with an appropriate code system.

  The invention according to claim 1 comprises a decoding means comprising an array of a plurality of types of graphic elements and performing a decoding process on a code represented on the medium by a plurality of code systems each using a predetermined type of graphic elements, and each of the code systems Storage means for storing processing content data indicating at least part of the content of the decoding process during decoding, and likelihood calculation means for calculating the likelihood of being described in each of the code systems according to the processing content data And an output means for outputting a decoding result in any one of the code systems according to the likelihood.

  According to a second aspect of the present invention, in the code recognition apparatus according to the first aspect, the processing content data is in accordance with a display mode of the graphic element recognized as at least one type of graphic element used by each code system on the medium. It is a value to be determined, and the likelihood calculating means calculates the likelihood such that the likelihood increases as the variation of the value decreases.

  According to a third aspect of the present invention, in the code recognition device according to the second aspect, the code represented on the medium is a bar code composed of a plurality of types of bars or spaces, and the processing content data includes It is a value determined according to the width of the bar or space recognized as at least one type of bar or space used by each code system in the bar code represented on the medium.

  According to a fourth aspect of the present invention, in the code recognition device according to the third aspect, the value is determined for each predetermined area of the bar code according to a width of the bar or space in the bar code represented on the medium. A threshold value for determining the type of width of the bar or space of the barcode is indicated.

  According to a fifth aspect of the present invention, in the code recognition device according to the first aspect, the processing content data indicates an amount of calculation required to decode the code, and the likelihood calculating means has a small amount of the calculation. The likelihood is calculated so that the likelihood becomes higher.

  According to a sixth aspect of the present invention, in the code recognition device according to the fifth aspect, the code represented on the medium is a bar code including a plurality of types of bars or spaces, and the decoding means includes the bar Decoding processing is performed based on the arrangement of bars and spaces read from a plurality of reading lines in the code, and the amount of calculation is derived according to the number of reading lines required until the bar code is decoded. Features.

  The invention according to claim 7 is a decoding step comprising a plurality of types of graphic elements arranged and performing a decoding process on a code represented on the medium using a plurality of code types each using a predetermined type of graphic elements; A storage step of storing in the storage means data indicating at least a part of the content of the decoding process during decoding, and a likelihood calculating step of calculating a likelihood that the data is described in each of the code systems according to the data A program for causing a computer to execute an output step of outputting a decoding result in any of the code systems according to the likelihood.

  According to the first and seventh aspects of the invention, by calculating the likelihood of being described in the code system according to the processing content data indicating at least part of the content of the decoding process by each code system, the code is Since the described code system is judged, the code can be recognized with an appropriate code system.

  According to the invention of claim 2, since at least one kind of graphic element used in each code system uses, as processing content data, a variation in value determined according to a mode displayed on the medium, each code system During the decoding process, the likelihood of being described in the code system can be calculated.

  According to the invention of claim 3, the likelihood of being described in the code system from the variation of the value determined according to the width of at least one kind of bar or space of the bar code displayed on the medium Therefore, the likelihood can be accurately calculated in the case of a barcode.

  According to the invention of claim 4, it is described in the code system from the variation in threshold value determined for each predetermined area according to the width of at least one kind of bar or space of the bar code displayed on the medium. Therefore, the likelihood can be calculated by using a value generated in the barcode decoding process.

  According to the invention of claim 5, since the likelihood of being described in the code system is calculated according to the amount of computation required in the decoded code system, an appropriate code system can be efficiently converted from the decoded code system. Judgment can be made.

  According to the invention of claim 6, when the decoding process is performed based on the arrangement of the bar and the space where the barcode is read from the plurality of reading lines, the code is determined according to the number of the reading lines required for each decoded code system. Since the likelihood of being described in the system is calculated, an appropriate code system can be determined efficiently.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

  FIG. 3 is a block diagram showing a hardware configuration and a functional configuration of the barcode recognition apparatus 3 according to the embodiment of the present invention. Here, the code means a code representing a numerical value, a character, or the like by an array of a plurality of graphic elements. The barcode recognition device 3 that recognizes a barcode composed of an array of multiple types of bars and spaces is an aspect of the code recognition device. The code system is a rule for associating an array of a plurality of graphic elements with numerical values, characters, and the like.

  The barcode recognition device 3 includes a control unit 31, a storage unit 32, a barcode acquisition unit 33, and a communication unit 34. The barcode recognition device 3 in the present embodiment may be either a hand-held type or a stationary type barcode reader.

  The control unit 31 is a program control device such as a CPU (Central Processing Unit). The control unit 31 includes functional blocks of a decoding unit 31A, a decoded content storage processing unit 31B, a likelihood calculating unit 31C, and an output unit 31D. Each function is executed by executing a program according to the embodiment of the present invention. Is realized. This program may be provided by being stored in various computer-readable information storage media such as a CD-ROM and a DVD-ROM, or may be provided via communication means such as the Internet. Details of each function will be described later.

  The storage unit 32 includes a memory element such as a random access memory (RAM) and a read only memory (ROM), a hard disk, and the like. The storage unit 32 stores the program (software) executed by the control unit 31. The storage unit 32 also operates as a work memory that holds various data used in the process of the control unit 31. In addition, the storage unit 32 in the present embodiment is used as the decoded content storage unit 32A.

  The barcode acquisition unit 33 includes a light source such as an LED that irradiates light on a medium on which a barcode to be recognized is represented, and a light receiving element such as a CCD that captures reflected light from the barcode. The barcode acquisition unit 33 irradiates the medium on which the barcode is displayed with light, and the reflected light is received by a light receiving element such as a CCD to acquire the barcode. Further, the barcode acquisition unit 33 acquires a barcode from data in an image format (hereinafter referred to as a barcode image) that generally captures the barcode represented on a paper medium or the like. The barcode acquired by the barcode acquisition unit 33 is provided to the control unit 31 as a target for decoding processing or the like.

  The communication unit 34 is configured by a network board or the like. The communication unit 34 has a function of exchanging various data such as transmitting the result of the decoding process stored in the storage unit 32 to another server or the like via the network.

  Here, the functions realized by the decoding unit 31A, the decoded content storage processing unit 31B, the likelihood calculating unit 31C, and the output unit 31D included in the control unit 31 of the barcode recognition device 3 will be described with reference to FIGS. I will explain. FIG. 4 shows a barcode image in which the quality of the barcode to be recognized is poor and each bar or space has a different width depending on each position. Furthermore, the figure shows a state in which line data indicating the arrangement of bars or spaces is read from seven reading lines. Next, FIG. 5 shows a process of decoding the barcode image of FIG. 4 by the NW7 code system and its result (FIG. 5A), a process of decoding by the CODE128 code system and its result (FIG. 5). 5 (b)).

  The decoding unit 31A decodes the barcode read by the barcode acquisition unit 33 according to a plurality of code systems set in advance to perform decoding processing. Here, the decoding process refers to a process of decoding a code composed of an array of a plurality of graphic elements read from a medium according to a predetermined code system. Specifically, the decoding unit 31A sets a plurality of reading lines for reading the arrangement of the bars and spaces for the barcode image as shown in FIG. The bar code is decoded according to line data at a plurality of locations indicating the space arrangement. This read line is a line that is at least one pixel wide and is virtually drawn in the length direction of the barcode (longitudinal direction of the barcode) from the barcode start position to the barcode end position. . The decoding unit 31A obtains a decoding result of each reading line by associating line data read from each reading line of the barcode image with an array of bars and spaces representing characters and numbers according to each code system, and obtains a barcode. Decode.

  FIG. 5A shows the result of decoding the bar code or the space arrangement indicated by the line data read in accordance with each read line in accordance with the NW7 code system (read line decode result) and decoding the bar code (read line 1). (Decoding result determined from ˜7). FIG. 5B similarly shows a case where decoding is performed according to the CODE128 code system. The character string associated with each reading line shown in FIG. 5A and FIG. 5B is subjected to the decoding process of the decoding unit 31A, for each character, the arrangement of bars or spaces in the line data, This is obtained by associating with an array of bars or spaces indicating character strings. In addition, the “x” mark in FIG. 5 indicates that there is no bar or space arrangement indicating the associated character string in the arrangement of the bars or spaces in the character.

  As shown in the figure, there are cases where each line data is identified as a different character string or includes characters that cannot be identified depending on the line data. Therefore, the decoding unit 31A determines a character for each character in accordance with the decoding results obtained by a plurality of reading lines. As shown in FIG. 5, this determination is made by determining the character having the largest number among the decoding results of each of the plurality of reading lines in all characters in the barcode. In addition, when the character having the maximum number cannot be determined, the decoding unit 31A newly sets a reading line, acquires the decoding result, and repeats the process of determining the character having the maximum number for each character again. When decoding has been performed, the decoding unit 31A stores the decoded code system and the barcode decoding result in the storage unit 32 in association with each other.

  Note that the decoding unit 31A performs decoding processing using another code system when the barcode cannot be decoded even if the decoding results of the predetermined number of reading lines are acquired. In determining the character for each character, in the above description, the determination is made based on whether or not the character is the largest in the decoding result by the plurality of reading lines. For example, the majority in the decoding result by three or more reading lines. It may be determined by other methods such as determining whether or not there is a character occupying.

  The decoded content storage processing unit 31B causes the decoded content storage unit 32A to store at least a part of the content of the decoding process as processed content data when the decoding unit 31A performs the decoding process of each code system. This processing content data is information used in the barcode decoding process or generated during the process, and information indicating the decoding process itself. Specifically, the processing content data is data determined according to the graphic element display mode on the medium, such as the bar width in the barcode, and data indicating the amount of calculation required for the decoding process. Here, in the case of the decoding process by the NW 7 (FIG. 5A), the decoded content storage processing unit 31B uses “7”, which is the number of read lines, as data indicating the amount of calculation required for the decoding process. The data is stored in the decoded content storage unit 32A. Similarly, in the case of decoding processing by CODE 128 (FIG. 5B), “4”, which is the number of read lines, is stored in the decoded content storage unit 32A.

  The likelihood calculating unit 31C uses the processing content data stored in the decoded content storage unit 32A to determine in which code system the barcode is described, and the likelihood that the barcode is described in each code system. Is calculated. Here, the likelihood refers to a measure of likelihood. The likelihood of being described in each code system is specifically “D2 + / $. / +: B” which is a decoding result when decoding is performed with the NW7 code system shown in FIG. This is a measure for determining the likelihood of a character string that can be decoded from an array indicating the original bar or space of the barcode. Generally, the latter has a larger number of read lines required for the decoding process when the barcode is decoded with the code system originally described and when the barcode is decoded with a code system different from the code system. Therefore, the likelihood calculating unit 31C, for example, by taking the reciprocal of the number of reading lines required for decoding, the likelihood described in NW7 and the likelihood described in CODE128 The likelihood is calculated to be high.

  The output unit 31D outputs, to the storage unit 32, the barcode decoding result based on the code system having the highest likelihood calculated by the likelihood calculating unit 31C. Specifically, the output unit 31D outputs “B01234456789n” as the barcode decoding result by the code system having the highest likelihood as the barcode decoding result by the CODE128.

  FIG. 6 is a diagram showing an example of the flow of the decoding process. First, a code system for decoding a barcode and a decoding direction are determined (S601). Next, the decoding unit 31A sets a reading line and acquires line data (S602). Further, the decoding unit 31A decodes the acquired line data (S603). In step S604, it is determined whether the barcode has been decoded using the line data decoding result in step S603. If the barcode can be decoded in S604 (YES), the number of times the line data is acquired by setting the reading line and the barcode decoding result are stored in the storage unit 32 (S605), and the process of S607 is performed. Execute. On the other hand, if the barcode could not be decoded in S604 (NO), it is determined whether or not the number of acquisition times of line data spent for the decoding process by the code system exceeds a predetermined number (S606). If the predetermined number of times is not exceeded (NO), line data is acquired again (S602), and the decoding process using the code system is continued. If the predetermined number of times is exceeded in S606 (YES), it is determined that the barcode cannot be decoded by the code system, and the processing in the next S607 is executed.

  In S607, it is determined whether or not the barcode decoding process has been executed from both the left and right sides of all the code systems that are set to be decoded in advance, and there is a decoding process that has not been executed yet. In (NO), the process returns to S601. When decoding processing is executed from the left and right in all code systems (YES), the likelihood is determined from the number of line data acquisitions stored in S605, and the decoding result with the highest likelihood is output ( S608).

  In the above, the likelihood that the likelihood calculating unit 31C is described in the code system is determined by using the number of read lines required for the decoding process of each code system as the processing content data. A case will be described in which the content data is data determined according to the display mode of the graphic element on the medium.

  The decoding unit 31A reads the arrangement of the bar or space from the reading line, and associates the arrangement of the bar or space with the arrangement of the bar or space indicating the character string for each character. In this association, the decoding unit 31A first sets a threshold value for determining the type of each bar and each space read from the reading line. As a result, among the bars read from the reading line, the bars exceeding the threshold width and the bars not exceeding the threshold width are recognized as different types of graphic elements. This threshold value is determined by a predetermined method in each code system. However, in the case of the NW7 code system in the present embodiment, since there are two types of bars, The average value of the width with the thinnest bar is set as a threshold value and determined for each character.

  FIG. 7 shows threshold values determined for each character when decoding from the right side to the left side using the NW7 code system (FIG. 7A), and for each character when decoding from the left side to the right side using the CODE 128 code system. The thresholds determined are shown in FIG. 7 (b). The threshold value of NW7 shown in FIG. 5A is a threshold value for judging two types of bars. The threshold value of CODE 128 shown in FIG. 4B is a threshold value for determining the thinnest bar and the second thinnest bar among the four types of bars.

  The decode content storage processing unit 31B causes the decode content storage unit 32A to store the threshold value for each character when decoding by each code system as the processing content data generated in the course of the decoding process by the decode unit 31A.

  Next, the likelihood calculating unit 31C obtains the standard deviation of the threshold value as a variation amount from the threshold value for each character stored in the decoded content storage unit 32A. Here, the bar code that is recognized as one type of bar used in each code system, when the barcode is decoded with the code system originally described, and when the code system is decoded with a different code system. In general, the latter has a tendency for the variation amount such as the width to be larger. Accordingly, the likelihood calculating unit 31C calculates the reciprocal of the standard deviation as the likelihood of being described in each court system. The variation amount of the threshold value may be another statistic such as variance, or any value that expresses variation such as a value such as a threshold range.

  Then, the output unit 31D outputs, to the storage unit 32, the decoding result by the CODE 128, which is a code system having a high likelihood because the standard deviation of the threshold value for each character is smaller than that of the NW7.

  In the embodiment described above, the threshold value is obtained for each character. However, the threshold value may be obtained for each predetermined area where a plurality of characters in the barcode are one area. In the above description, the threshold is determined according to the width of the bar or space obtained from the line data. For example, the bar width displayed on the medium is the width of each bar, which is at least one type of graphic element. As a value determined according to the display mode, the likelihood calculating unit 31C may obtain the likelihood from the variation amount of the value.

  When reading the arrangement of bars and spaces from a plurality of reading lines in the decoding process of the decoding unit 31A, the decoding content storage processing unit 31B stores the threshold value obtained for each character on any one reading line. Alternatively, the threshold values for all the reading lines may be stored. Further, an average value of threshold values obtained from all the reading lines may be stored as the threshold value.

  FIG. 8 is a diagram illustrating an example of a processing flow of the control unit 31 in the present embodiment. First, from among a plurality of code systems stored in the storage unit 32 as an initial setting, a code system for decoding the barcode acquired by the barcode acquisition unit 33 is set (S801). Next, the decoding unit 31A decodes the barcode according to the code system set in S801 (S802). In step S803, it is determined whether the barcode has been decoded. If it can be decoded (YES), it is further determined whether or not there is a margin of a predetermined width on the left and right of the barcode (S804). Here, the reason for checking the left and right margins of the bar code is to prevent a case where only a part of the bar code is erroneously decoded as being decoded. When the left and right margins are confirmed (YES), the control unit 31 temporarily stores the decoding result in the storage unit 32 (S805). Here, the threshold derived for each character to identify the type of bar used for decoding is stored in the decoded content storage unit 32A as processing content data (S806). Further, the number of read lines set until the end of the decoding process is stored in the decode content storage unit 32A as process content data (S807).

  If decoding is not possible in S803 (NO), if a margin of a predetermined width does not exist in the margin check in S804 (NO), and if a decoding result or the like is stored in step S805 or the like, in S808, It is determined whether or not the decoding process for all the initially set code systems has been completed. If there is a code system for which the decoding process has not been completed (NO), the process returns to S801 again to perform a decoding process using another code system.

  If it is determined in S808 that the decoding process for all the code systems has been completed (YES), it is first determined whether or not the decoding is performed using a plurality of code systems (S809). When the decoding is performed with only one code system (NO), the output unit 31D outputs the decoding result based on the code system to the storage unit 32 (S815). However, when decoding is possible with a plurality of code systems (YES), it is necessary to determine which code system is the content originally indicated by the barcode. Therefore, the code system from which the decoding result is to be obtained is determined from the decoding processing content data stored in S806 or S807 (S810, etc.).

  First, in S810, dispersion of threshold values for identifying the type of bar obtained for each character in a plurality of decoded code systems is obtained. If the smallest value among the obtained variance values is more than a certain difference from other variance values (YES), a code system with a small variance is determined (S811), and the code system depends on the code system. The decoding result is output to the storage unit 32 (S815).

  If it is difficult to compare the variance values (NO), the number of read lines required until the decoding is completed is compared (S812). Then, when the smallest number of the read lines is more than a certain difference from others (YES), the code system having the smallest number of read lines is determined (S813). The decoding result based on the code system is output to the storage unit 32 (S815). Furthermore, if the code system cannot be determined despite the comparison of the number of read lines (NO), among the multiple code systems that can be decoded, the one with the least error recognition due to the characteristics of the code system. As a determination (S814), the decoding result is output to the storage unit 32 (S815).

  In the above embodiment, the decoding unit 31A sets the reading line in the barcode image, acquires the line data, and performs the decoding process. However, the decoding unit 31A does not acquire the barcode image. However, it is also possible to set the reading line to the barcode displayed on the medium and directly acquire the line data to perform the decoding process.

  The technical idea of the present invention is not limited to a bar code, but may be a code composed of an array of a plurality of types of graphic elements. It is a two-dimensional code such as a so-called QR (Quick Response) code. There may be a color code.

It is a figure which shows an example in case another kind of barcode is contained in a part of predetermined barcode. It is a figure which shows an example in case a predetermined | prescribed barcode can be recognized with two types of code systems. It is a figure which shows an example of the functional block which shows the function which the barcode recognition apparatus concerning this embodiment implement | achieves. It is a figure which shows an example of the barcode image concerning this embodiment. It is a figure which shows the process of decoding a barcode image, and the example of a result concerning this embodiment. It is a figure which shows an example of the flow of a decoding process concerning this embodiment. It is a figure which shows the mode of the threshold value determined for every character which generate | occur | produces by the decoding process concerning this embodiment. It is a figure which shows an example of the flow of a process of the barcode recognition apparatus concerning this embodiment.

Explanation of symbols

  3 Bar code recognition device, 31 control unit, 31A decoding unit, 31B decoded content storage processing unit, 31C likelihood calculation unit, 31D output unit, 32 storage unit, 32A decoded content storage unit, 33 barcode acquisition unit, 34 communication unit .

Claims (7)

A decoding means comprising an array of a plurality of types of graphic elements, and performing a decoding process on a code represented on the medium by a plurality of code systems each using a predetermined type of graphic elements;
For each code system, storage means for storing processing content data indicating at least part of the content of decoding processing during decoding;
Likelihood calculating means for calculating the likelihood of being described in each of the code systems according to the processing content data;
Output means for outputting a decoding result in any of the code systems according to the likelihood;
A code recognition device comprising: The code recognition device according to claim 1.
The processing content data is a value determined according to a display mode in the medium of a graphic element recognized as at least one type of graphic element used by each code system,
The likelihood calculating means calculates the likelihood so that the likelihood increases as the variation of the value decreases.
A code recognition apparatus characterized by the above. The code recognition device according to claim 2,
The code represented on the medium is a bar code composed of an array of multiple types of width bars or spaces,
The processing content data is a value determined according to a width of the bar or space represented on the medium of the bar or space recognized as at least one type of bar or space used by each code system,
A code recognition apparatus characterized by the above. The code recognition device according to claim 3,
The value is determined for each predetermined region of the barcode according to the width of the barcode represented on the medium of the bar or space, for determining the type of width of the bar or space of the barcode Indicating the threshold,
A code recognition apparatus characterized by the above. The code recognition device according to claim 1.
The processing content data indicates the amount of calculation required to decode the code,
The likelihood calculating means calculates the likelihood so that the likelihood increases as the amount of the operation decreases.
A code recognition apparatus characterized by the above. The code recognition apparatus according to claim 5.
The code represented on the medium is a bar code composed of an array of multiple types of width bars or spaces,
The decoding means performs a decoding process based on the arrangement of bars and spaces read from a plurality of reading lines in the barcode,
The amount of computation is derived according to the number of read lines required to decode the barcode.
A code recognition apparatus characterized by the above. A decoding step consisting of an array of a plurality of types of graphic elements, and performing a decoding process on a code represented on the medium with a plurality of code systems each using a predetermined type of graphic elements;
For each code system, a storage step of storing in the storage means data indicating at least part of the content of the decoding process during decoding;
A likelihood calculating step for calculating the likelihood of being described in each of the code systems according to the data;
An output step of outputting a decoding result in any of the code systems according to the likelihood;
A program that causes a computer to execute.

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