JP5686346B2 - Two-dimensional code generation method, two-dimensional code generation device, program, and storage medium - Google Patents

Description

  The present invention relates to a two-dimensional code generation method, a two-dimensional code generation device, a program, and a storage medium, and more particularly to a technique suitable for use in generating a two-dimensional code reflecting a photograph or an illustration.

  Conventionally, QR code (registered trademark), which is a kind of two-dimensional code, has been widely used, and therefore, the visual incentive tends to decrease as an advertising medium. Therefore, in recent years, in order to improve the visual incentive, a two-dimensional code with high decorativeness in which a photograph or an illustration is incorporated in the QR code has been proposed. As described above, by enhancing the decorativeness of the two-dimensional code, it is possible to easily identify the information stored in the two-dimensional code before reading, or to improve the visibility and produce the originality.

  On the other hand, when a photograph or illustration is incorporated, the incorporated portion is masked, so that it is necessary to decode it using an error correction function when reading a two-dimensional code. As described above, since there are restrictions on the size and position of photographs and illustrations, a technique that optimizes the positions of photographs and illustrations on a two-dimensional code and achieves both decorativeness and readability has been proposed. ing.

  However, in the conventional method, it is necessary to use the error correction function even when the position where the photograph or illustration is arranged is optimized. In recent years, two-dimensional codes such as QR codes are used not only for homepages but also for printing media such as magazines and business cards. In such cases, the printing media may be dirty or distorted. When a part of a two-dimensional code in which a photograph or an illustration is incorporated is damaged or distorted, there is a problem that the decoding rate is lowered. Therefore, it is desirable to be able to perform decoding without using an error correction function as much as possible, assuming such a situation.

  Therefore, a technique for ensuring decoration and readability by forming a cell pattern similar to a photograph or illustration in a two-dimensional code using only the padding code word area instead of arranging a photograph or illustration is also disclosed. Has been.

JP 2009-163720 A JP 2009-230729 A JP 2007-241329 A Japanese Patent No. 3957735

  However, the area of the padding code word greatly varies depending on the data embedded in the two-dimensional code and the total number of error correction code words. Therefore, depending on the amount of data, the padded codeword area may be relatively small. Further, as described above, when used for a printing medium such as a magazine or a business card, the error correction level is increased assuming that a part of the two-dimensional code is damaged or distorted. The area of grass code words is reduced. In such a case, there is a problem that there are many restrictions such as a cell pattern similar to a photograph or illustration cannot be formed unless the model number is increased or the error correction level is lowered. Further, the error correction code word area is not subject to transformation.

  An object of the present invention is to make it possible to generate a two-dimensional code similar to a target image or pattern more freely in view of the above-described problems.

The two-dimensional code generation method of the present invention includes a plurality of components including an input step for inputting data and an image, and an error correction level, a mask pattern, a model number, and a padding code word related to generation of a cell arrangement pattern. A solution candidate generation step for generating a two-dimensional code in which the data is encoded as a solution candidate as a variable, and a solution candidate for evaluating whether the solution candidate generated in the solution candidate generation step is similar to the image An evaluation step, and when the solution candidate generation step evaluates that the image is not similar to the image in the solution candidate evaluation step, at least the error correction level, mask pattern, model number, and padding code word the generating a new solution candidate by using an optimization algorithm with a variable, it said in solution candidate evaluation process, which is generated in the solution candidate generation step And evaluating the was Do candidate solutions.

The two-dimensional code generation apparatus of the present invention includes a plurality of components including an input means for inputting data and an image, and an error correction level, a mask pattern, a model number, and a padding code word related to generation of a cell arrangement pattern. Solution candidates generating means for generating a two-dimensional code obtained by encoding the data as solution candidates, and solution candidates for evaluating whether the solution candidates generated by the solution candidate generation means are similar to the image Evaluation means, and when the solution candidate evaluation means evaluates that the solution candidate evaluation means is not similar to the image, at least the error correction level, mask pattern, model number, and padding codeword generating a new solution candidates based on the plurality of components using an optimization algorithm with a variable, the solution candidate evaluating means, by the candidate solution generating means And evaluating the made a new candidate solutions.

  The program of the present invention causes a computer to execute each step of the two-dimensional code generation method.

  The storage medium of the present invention stores the program.

  According to the present invention, it is possible to generate a two-dimensional code similar to an input image and a two-dimensional code including a designated pattern.

It is a block diagram which shows the hardware structural example of the two-dimensional code production | generation apparatus which concerns on embodiment of this invention. It is a block diagram which shows the function structural example of the two-dimensional code production | generation apparatus which concerns on embodiment of this invention. 5 is a flowchart illustrating an example of a processing procedure for generating a plurality of patterns of two-dimensional codes as an initial group in the embodiment of the present invention. It is a figure which shows the list of error correction levels. 6 is a flowchart illustrating an example of a processing procedure for generating a two-dimensional code output by a genetic algorithm in the embodiment of the present invention. It is a figure explaining the target area | region, boundary area | region, and background area | region of the image input. It is a figure explaining Genotype and Phenotype. It is a figure which shows an example of the two-dimensional code of the pattern similar to the two-dimensional code and illustration which affixed the illustration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, description will be made with reference to a QR code which is a kind of two-dimensional code.
FIG. 1 is a block diagram illustrating a hardware configuration example of a two-dimensional code generation device 100 according to the present embodiment.
In FIG. 1, a CPU 101 controls the entire two-dimensional code generation apparatus 100, reads a program stored in a ROM 103 when necessary, expands it in a RAM 102, and executes processing according to the present embodiment. The input device 104 can be loaded with a removable recording medium such as a memory card, and inputs data to be embedded in a two-dimensional code or inputs a photograph or illustration to be formed as a cell pattern.

  The operation unit 105 is an operation member that inputs a command in accordance with a user operation. The storage device 106 is a hard disk, for example, for storing data. The image display device 107 is, for example, a liquid crystal display, and displays a warning message indicating that a two-dimensional code cannot be generated, or displays a menu screen for setting a two-dimensional code condition or the like. A network interface card (NIC) 108 is an interface for exchanging data with other information devices via the LAN 110. The main bus 109 is a bus for connecting the above-described components.

FIG. 2 is a block diagram illustrating a functional configuration example of the two-dimensional code generation device 100 according to the present embodiment.
In FIG. 2, a data input unit 201 inputs data (character string) to be embedded in a two-dimensional code from the input device 104 or an external device via the LAN 110.

  The solution candidate generation unit 202 generates a code word from the input character string, generates a plurality of two-dimensional codes using the model number, error correction level, mask pattern, and padding code word as variables, and a solution candidate storage unit 206. To remember. In this embodiment, although detailed description will be given later, a two-dimensional code that most reflects a desired photograph or illustration is generated from a plurality of such two-dimensional codes by a genetic algorithm.

  The image input unit 203 inputs image data such as photographs and illustrations from the input device 104 or an external device via the LAN 110. The solution candidate evaluation unit 204 evaluates the two-dimensional code using a genetic algorithm by comparing the two-dimensional code stored in the solution candidate storage unit 206 with the image data input by the image input unit 203. . The output unit 205 outputs the generated two-dimensional code.

FIG. 3 is a flowchart illustrating an example of a processing procedure for generating a plurality of patterns of two-dimensional codes as an initial group by the solution candidate generation unit 202.
First, in step S301, the process waits until a character string data is input from the data input unit 201 together with an instruction to generate a two-dimensional code. When character string data is input, a code word is generated in step S302 based on the input character string.

  Next, in step S303, a mode indicator and a character number indicator are added to the head of the generated code word. In step S304, a termination bit is added to the end of the generated code word.

  In step S305, a combination of an error correction level, a mask pattern, a model number, and a padding code word that does not affect readability is set at random. Note that a combination once applied is not selected again. As shown in FIG. 4, the error correction level can be set in four stages of L, M, Q, and H. Further, when the two-dimensional code is used for a printed matter or an article, the initial setting may be set to only two stages of Q and H in order to increase the error correction function. Good.

  Next, in step S306, the padding code word set in step S305 is generated and added after the end bit assigned in step S304. Note that the length of the padding code word is determined based on the model number and error correction level of the two-dimensional code. In addition, when a residual code word or a residual bit is necessary depending on the model number, a residual code word or a residual bit is added. Then, an error correction code word having the set error correction level is added. Here, the error correction code word is determined by the error correction level, the model number, the code word of the input character string, and the padding code word. Therefore, the information of these four elements can be changed by changing the error correction code word. In this embodiment, since the error correction level, the model number, and the like are handled as design variables in this way, the cell arrangement pattern in the error correction codeword area can also be changed. Next, in step S307, the bit string generated up to step S306 is divided into blocks, and an RS code is generated in each block.

  Next, in step S308, the generated code word is arranged on the symbol of the model number set in step S305. In the present embodiment, it is assumed that two colors of white and black are used as the cell color in order to facilitate binarization and ensure readability. In step S309, mask processing is performed according to the mask pattern set in step S305. In step S310, the format information and the model number information are arranged at predetermined positions on the symbol of the two-dimensional code, and a two-dimensional code as an initial group is generated.

  Next, in step S311, it is determined whether a predetermined number of two-dimensional codes have been obtained. If a predetermined number of two-dimensional codes are not obtained as a result of this determination, the process returns to step S305, and an error correction level, a mask pattern, a model number, and a padding code word are set by different combinations. On the other hand, when a predetermined number of two-dimensional codes are obtained, the processing by the initial group generation unit 202 is terminated. Note that the number of two-dimensional codes necessary for the initial population is determined by parameters used in a genetic algorithm described later.

  Next, a method for generating a two-dimensional code reflecting the shape of a photograph or an illustration using a genetic algorithm based on the evaluation of the solution candidate evaluation unit 204 will be described. When the cell arrangement pattern is changed so as to reflect the shape of the photograph or illustration, the data inside the two-dimensional code is changed, so that the readability is lowered. Therefore, in order to change the cell arrangement pattern while maintaining readability, it is necessary to change the internal configuration data of the two-dimensional code.

  Therefore, in this embodiment, the error correction level, the mask pattern, the model number, and the padding code word that affect the cell arrangement pattern and do not affect the readability are set as the design variables of the genetic algorithm as constituent elements, and by the genetic algorithm, A two-dimensional code reflecting the inputted photograph or illustration is generated.

FIG. 5 is a flowchart illustrating an example of a processing procedure in which the solution candidate evaluation unit 204 evaluates a solution candidate of a two-dimensional code using a genetic algorithm.
First, in step S501, image data such as a photograph or an illustration is input from the image input unit 203.

  Next, in step S502, the solution candidate evaluation unit 204 compares the two-dimensional code stored in the solution candidate storage unit 206 with the image data input in step S501, and the following equation (1) and equation: The fitness Q (C) indicating the similarity is calculated by (2).

  Here, O (x, y) is an actual gradation value in the two-dimensional code, and T (x, y) is an ideal gradation value as an output two-dimensional code. H and W represent the numbers of vertical and horizontal pixels, respectively. In the present embodiment, the threshold ε is set to a value that is small enough to repeat generation and evaluation of solution candidates until they are similar to the input image, and to be regarded as similar.

Further, ω represents a gradation value in the weighted image and is a value calculated from the input image. As shown in FIG. 6, the input image is divided into a target area 601, a boundary area 602, and a background area 603. The method of calculating the gradation value omega differs by these regions, the gradation value omega _target at the target area 601, the gradation value omega _back of a gray level value of omega _border and the background region 603, in the boundary region 602, It is calculated by the following equation (3).

Here, S _all is the area of the two-dimensional code, and S _target is the area of the target region 601 to be mainly expressed in the image. S _back is the area of the other background region 603.

  Next, in step S503, the solution candidate evaluation unit 204 reads two two-dimensional codes at random from the two-dimensional codes stored in the solution candidate storage unit 206. Then, the child two-dimensional code generated immediately before by crossover and mutation in step S504, which will be described later, is read from the solution candidate storage unit 206. Then, the two-dimensional code having the highest fitness is selected from the four of the two-dimensional codes of the child and the read two-dimensional codes, and one two-dimensional code is selected by roulette. Here, when one two-dimensional code is selected by the roulette, the specific gravity is set higher in the order of higher fitness, and the two-dimensional code with higher fitness is selected with higher probability.

  Next, in step S504, the solution candidate generation unit 202 uses the two two-dimensional codes selected in step S503 as parents, and generates child individuals by crossover. Then, 3% mutation is caused in all the genes (error correction level, mask pattern, model number and padding code word) of the generated child individuals.

FIG. 7 is a diagram for explaining Genotype and Phenotype.
In the crossover and mutation in step S504, as shown in FIG. 7, the error correction level, the mask pattern, the model number, and the padding code word are manipulated expressed in Genotype. In this case, the error correction level, the mask pattern, and the model number are fixed lengths, which are 2 bits, 3 bits, and 6 bits, respectively. On the other hand, the padding code word has a variable length because it depends on the model number, the error correction level, and the number of characters of the embedded data. As a method of crossover, a child individual is generated using uniform crossover. In the mutation, the bit is inverted with a probability of 3% for each bit as a design variable. In step S <b> 505, the solution candidate generation unit 202 encodes the generated child individual into a two-dimensional code that is a Phenotype and stores it in the solution candidate storage unit 206.

  Next, in step S506, the solution candidate evaluation unit 204 determines whether or not a two-dimensional code having a fitness exceeding a predetermined value is obtained as a result of repeating the genetic manipulation. As a result of the determination, if a two-dimensional code having a fitness level exceeding a predetermined value is obtained, it is regarded as being similar to the input image. In step S507, the two-dimensional code is output from the output unit 205, and the process finish. As an output method, a two-dimensional code that is a solution candidate may be displayed on the image display device 107 or may be transmitted to an external device via the LAN 110.

  On the other hand, as a result of the determination in step S506, if a two-dimensional code having a fitness level exceeding a predetermined value is not obtained, it is regarded that they are not similar, and the process returns to step S502 and the process is repeated until a desired two-dimensional code is obtained. . Thereafter, in step S502, an adaptive value may be calculated only for a two-dimensional code whose fitness is not calculated, such as a child two-dimensional code.

  FIG. 8A is a diagram illustrating an example of a two-dimensional code pasted with characters, and FIG. 8B is a diagram illustrating an example of a two-dimensional code generated by the method according to the present embodiment. As shown in FIG. 8, the method according to the present embodiment can generate a two-dimensional code with a pattern similar to “2”.

  As described above, according to the present embodiment, a two-dimensional code that most reflects a photograph or illustration is generated by a genetic algorithm using an error correction level, a mask pattern, a model number, and a padding code word as variables. As a result, not only the padding code word area but also the error correction code word area can be rearranged, and a two-dimensional code reflecting photographs and illustrations can be generated within a less restrictive range.

  In the present embodiment, a two-dimensional code reflecting a photograph or an illustration is generated by a genetic algorithm, but other algorithms may be used as long as the algorithm repeats generation and evaluation of solution candidates. As an algorithm to optimize by generating and evaluating candidate solutions through trial and error in this way, a single point search algorithm such as a random method, a simplex method, a hill climbing method, an annealing method, a tabu search, or the like, Examples include multi-point search algorithms such as genetic algorithms, particle swarm optimization, and ant colony optimization.

  In the present embodiment, a plurality of two-dimensional codes of the initial group are generated. However, depending on the type of algorithm, it may not be necessary to generate a two-dimensional code of the initial group. When the generation and evaluation of solution candidates are repeated using such an algorithm, it is not necessary to generate a plurality of two-dimensional codes as an initial group by the processing shown in FIG.

  Furthermore, in the present embodiment, the QR code has been described as an example. Similarly, for other two-dimensional codes, the constituent elements related to the generation of the pattern forming the symbol can be changed to generate and evaluate the solution candidates. Similar effects can be obtained by repetition.

  In this embodiment, the error correction level, mask pattern, model number, and padding code word that do not affect the readability are set as design variables. However, in addition to these four design variables, a remaining code word, a remaining bit It is good also as a design variable including. On the other hand, there are cases where the two-dimensional code is not damaged or distorted depending on the application, and there are situations where the error correction function is rarely used. Further, depending on the photograph or illustration, there may be a case where a desired two-dimensional code cannot be obtained easily by an algorithm. Further, as a use other than the decoration of the two-dimensional code, there is a case where a specific pattern is desired to be embedded in the entire region of the two-dimensional code for the purpose of generating a two-dimensional code resistant to distortion. When such a condition is satisfied, it is desirable to generate a two-dimensional code close to the target image even if the data readability is somewhat affected. Therefore, in such a case, all the components constituting the two-dimensional code may be used as design variables.

(Other embodiments)
Each means constituting the two-dimensional code generation device and each step of the two-dimensional code generation method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable storage medium storing the program are included in the present invention.

  In addition, the present invention can be implemented as, for example, a system, apparatus, method, program, storage medium, or the like. Specifically, the present invention may be applied to a system including a plurality of devices. The present invention may be applied to an apparatus composed of a single device.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowcharts shown in FIGS. 3 and 5) for realizing the functions of the above-described embodiments may be supplied directly or remotely to the system or apparatus. Including. This includes the case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  Examples of the storage medium for supplying the program include a flexible disk, a hard disk, an optical disk, and a magneto-optical disk. Further, there are MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, there is a method of connecting to a homepage on the Internet using a browser of a client computer. It can also be supplied by downloading the computer program itself of the present invention or a compressed file including an automatic installation function from a homepage to a storage medium such as a hard disk.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  As another method, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and encrypted from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to download the key information to be solved and use the key information to execute the encrypted program and install it in the computer.

  Further, the functions of the above-described embodiments are realized by the computer executing the read program. Furthermore, based on the instructions of the program, an OS or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.

  Further, as another method, a program read from a storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, and the function is based on the instructions of the program. A CPU or the like provided in the expansion board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

201 Data Input Unit 202 Solution Candidate Generation Unit 203 Image Input Unit 204 Solution Candidate Evaluation Unit 205 Output Unit 206 Solution Candidate Storage Unit

Claims (6)

An input process for inputting data and images;
A solution candidate that generates a two-dimensional code in which the data is encoded as a solution candidate using a plurality of components including an error correction level, a mask pattern, a model number, and a padding code word, which are related to generation of a cell arrangement pattern. Generation process;
A solution candidate evaluation step for evaluating whether the solution candidate generated in the solution candidate generation step is similar to the image,
In the solution candidate generation step, when it is evaluated that the solution candidate evaluation step does not resemble the image, an optimization algorithm using at least the error correction level, the mask pattern, the model number, and the padding codeword as variables Generate a new solution candidate using
In the solution candidate evaluation step, a new solution candidate generated in the solution candidate generation step is evaluated.   2. The two-dimensional code generation method according to claim 1, wherein, in the solution candidate evaluation step, the similarity with the image is calculated to evaluate whether or not they are similar.   In the solution candidate generation step, when it is evaluated that the image is not similar to the image in the solution candidate evaluation step, a new solution candidate is generated based on the plurality of components and the calculated similarity The two-dimensional code generation method according to claim 2, wherein: Input means for inputting data and images;
A solution candidate that generates a two-dimensional code in which the data is encoded as a solution candidate using a plurality of components including an error correction level, a mask pattern, a model number, and a padding code word, which are related to generation of a cell arrangement pattern. Generating means;
Solution candidate evaluation means for evaluating whether the solution candidate generated by the solution candidate generation means is similar to the image;
When the solution candidate generation unit evaluates that the solution candidate evaluation unit does not resemble the image, an optimization algorithm using at least the error correction level, the mask pattern, the model number, and the padding codeword as a variable used to generate a new solution candidates based on said plurality of component elements,
The solution candidate evaluation means evaluates a new solution candidate generated by the solution candidate generation means.   A program for causing a computer to execute each step of the two-dimensional code generation method according to claim 1.   A computer-readable storage medium storing the program according to claim 5.

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